Hi RandomSanity,
I would keep in mind that there is no specific type or category of mattress that is “best for back pain” in general because each person’s individual needs and preferences in terms of “comfort”, firmness, and PPP (Posture and alignment, Pressure relief, and Personal preferences) is unique to them. There is only a mattress that is “best for your back pain”. The choice between different materials or components in a mattress or types of mattress is always a preference and budget choice rather than a “better/worse” choice (see this article).
All the different types or categories of mattress (including memory foam mattresses) have hundreds of different options and designs and some of them that work well for some people with back pain may be completely unsuitable for other people with back pain to sleep on even if they have a similar body type and sleeping style. In other words the specific design of a mattress and whether that specific design is a good match for you in terms of PPP (regardless of whether it would be suitable for anyone else) is always more important than the type of materials and components inside the mattress.
Most of the Tempurpedic mattresses use good quality materials but as you know they are in much higher (and mostly unjustifiable) budget ranges and for most people they certainly wouldn’t be in the best “value” range compared to many other smaller manufacturers that use similar (or in some cases better) quality materials that are in much lower budget ranges. You can read more about Tempurpedic in general in posts #1 and #2 here.
Having said that … Tempurpedic doesn’t disclose the quality/density of the memory foam and polyfoam comfort and transition layers in their Tempur Flex mattresses but I believe the polyfoam layer that they use underneath their memory foam is 1.6 lb density which would be a lower density and less durable material than I would normally like to see in a one sided mattress (see the quality/durability guidelines here) and I would normally avoid any mattress that has more than “about an inch or so” of lower quality or “unknown” materials in the upper layers of the mattress (especially in this budget range) because it could reduce and compromise the durability and useful life of the mattress.
While other people’s comments about the knowledge and service of a particular business can certainly be very helpful … I would always keep in mind that you are the only one that can feel what you feel on a mattress and I would be cautious about about using other people’s experiences or reviews on a mattress (either positive or negative) or review sites in general (with or without videos) as a reliable source of information or guidance about how you will feel on the same mattress or how suitable or how durable a mattress may be for you and in many if not most cases they can be more misleading than helpful because most consumers have little knowledge about mattresses and mattress materials or how to assess the quality of the materials in a mattress and any mattress that would be a perfect choice for one person or even a larger group of people may be completely unsuitable for someone else to sleep on (even if they are in a similar weight range). In other words … reviews in general certainly won’t tell you much if anything about the suitability, quality, durability, or “value” of a mattress for any particular person (see post #13 here).
I would also keep in mind that there are also no “standard” definitions or consensus of opinions for firmness ratings and different manufacturers can rate their mattresses very differently than others so a mattress that one manufacturer rates as being a specific firmness could be rated very differently by another manufacturer. Different people can also have very different perceptions of firmness and softness compared to others as well and a mattress that feels firm for one person can feel like “medium” for someone else or even “soft” for someone else (or vice versa) depending on their body type, sleeping style, physiology, their frame of reference based on what they are used to, and their individual sensitivity and perceptions. There are also different types of firmness and softness that different people may be sensitive to that can affect how they “rate” a mattress as well (see post #15 here) so different people can also have very different opinions on how two mattresses compare in terms of firmness and and some people may rate one mattress as being firmer than another and someone else may rate them the other way around. This is all relative and very subjective and is as much an art as a science.
There is also more information in post #9 here about the different ways that one mattress can “match” or “approximate” another one. Every layer and component in a mattress (including the cover and any quilting materials) will affect the feel and performance of every other layer and component and the mattress “as a whole” so unless you are able to find another mattress that uses exactly the same type of materials, components, cover, layer thicknesses, layer firmnesses, and overall design (which would be very unlikely) then there really isn’t a way to match one mattress to another one in terms of “comfort”, firmness, and PPP based on the specifications of the mattresses (even assuming that you can find out all the specifications you would need for both mattresses you are comparing).
Mattress manufacturers generally try to differentiate their mattress from the mattresses made by other manufacturers and don’t normally try to “match” another mattress that is made by a different manufacturer so unless a manufacturer specifically says in their description of a mattress that one of their mattresses in the same general category is specifically designed to “match” or “approximate” another one in terms of firmness or “feel” and PPP and/or they are very familiar with both mattresses and can provide reliable guidance about how they compare based on the “averages” of a larger group of people that have compared them (different people may have very different opinions about how two mattresses compare) … the only reliable way to know for certain how two mattresses would compare for you in terms of how they “feel” or in terms of firmness or PPP would be based on your own careful testing or actual sleeping experience on both of them.
All of the mattresses you are considering are in a completely different category than any of the Tempurpedic Flex mattresses and use very different combinations of materials and components (see this article about the different types and categories of mattresses) so there really isn’t a way to make a meaningful comparisons between them because they would each have a very different “feel”.
When you can’t test a mattress in person then the most reliable source of guidance is always a more detailed conversation with a knowledgeable and experienced retailer or manufacturer that has your best interests at heart and who can help “talk you through” the specifics of their mattresses and the properties and “feel” of the materials they are using (fast or slow response, resilience, firmness etc) and the options they have available that may be the best “match” for you based on the information you provide them, any local testing you have done or mattresses you have slept on and liked or other mattresses you are considering that they are familiar with, and the “averages” of other customers that are similar to you. They will know more about “matching” their specific mattress designs and firmness levels to different body types, sleeping positions, and preferences (or to other mattresses that they are familiar with) than anyone else.
While I can certainly help with “how” to choose … it’s not possible to make specific suggestions or recommendations for either a mattress, manufacturers/retailers, or combinations of materials or components because the first “rule” of mattress shopping is to always remember that you are the only one that can feel what you feel on a mattress and there are too many unknowns, variables, and personal preferences involved that are unique to each person to use a formula or for anyone to be able to predict or make a specific suggestion or recommendation about which mattress or combination of materials and components or which type of mattress would be the best “match” for you in terms of “comfort” or PPP (Posture and alignment, Pressure relief, and your Personal preferences) or how a mattress will “feel” to you or compare to another mattress based on specs (either yours or a mattress), sleeping positions, health conditions, or “theory at a distance” that can possibly be more accurate than your own careful testing (hopefully using the testing guidelines in step 4 of the tutorial) or your own personal sleeping experience (see mattress firmness/comfort levels in post #2 here).
There is more about the 3 most important parts of “value” of a mattress purchase in post #13 here which can help you make more meaningful quality/value comparisons between mattresses in terms of suitability (how well you will sleep), durability (how long you will sleep well), and the overall value of a mattress compared to your other finalists based on suitability, durability, and all the other parts of your personal value equation that are most important to you (including the price of course and the options you have available after a purchase if your choice doesn’t turn out as well as you hoped for).
While I can’t speak to how any mattress will “feel” for someone else because this is too subjective and relative to different body types, sleeping positions, and individual preferences, sensitivities, and circumstances … outside of PPP the most important part of the value of a mattress purchase is durability which is all about how long you will sleep well on a mattress. This is the part of your research that you can’t see or “feel” and assessing the quality/durability and useful life of a mattress depends on knowing the specifics of its construction and the type and quality of the materials inside it regardless of the name of the manufacturer on the label (or how a mattress feels in a showroom or when it is relatively new) so I would always make sure that you find out information listed here so you can compare the materials and components to the quality/durability guidelines here to make sure there are no lower quality materials or weak links in a mattress that would be a cause for concern relative to the durability and useful life of a mattress before making any purchase.
There is more about all three of the mattresses you are considering and many of the other simplified choice mattresses in post #2 here in the simplified choice mattress topic. The first post in the same topic about simplified choice mattresses would be well worth reading as well.
The Casper mattress uses good quality materials that would be a suitable choice in terms of durability for those that are in more “average” weight ranges (lower 200’s or less). There is also more information about Casper in this topic and in this topic. A forum search on Casper (you can just click the link) will also bring up more comments and feedback about it as well.
There is also more information about the Loom & Leaf in post #5 here and I would be somewhat cautious with the Loom & Leaf because of the convoluted layer of 4 lb memory foam (which is less durable than a solid layer of the same material) in combination with their 1.5 lb base layer which is a lower density and less durable material than I would normally like to see in this budget range.
There is also more information about Novosbed’s new mattresses in post #4 here. They are a member of this site which means that I think highly of them and that I believe that they compete well with the best in the industry in terms of their quality, value, knowledge, service, and transparency. They also use good quality materials and there are no lower quality materials or weak links in their mattresses although the medium firmness option would be more suitable for higher weight ranges (more than the lower 200’s or so) in terms of the quality/density and durability of the materials.
I or some of the more knowledgeable members of the site can certainly help you to narrow down your options, help you focus on better quality/value choices that are available to you either locally or online, help you identify any lower quality materials or weak links in a mattress that you may be considering, act as a fact check, answer many of the specific questions you may have along the way that don’t involve what you will “feel” on a mattress, and help with “how” to choose but only you can decide which specific mattress, manufacturer, or combination of materials is “best for you” based on all the parts of your personal value equation that are most important to you.
If you are focusing on online mattresses then some of the better online options I’m aware of that ship across Canada are listed in post #21 here.
If you let me know your city or postal code I’d also be happy to let you know about the better local options or possibilities I’m aware of in your area.
Phoenix