Hi InfMur,
I’m glad you found us before you ended up purchasing a major brand mattress which tend to use lower quality materials that would be a weak link in the mattress which can compromise the durability and useful life of the mattress.
There are 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 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.
When you can’t test a mattress in person then the most reliable source of guidance is always a more detailed phone 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.
The tutorial post also includes a list of the members here that sell mattresses online (in the optional online step) and several of them also sell pocket coil hybrid mattresses (using latex or memory foam comfort layers) that may be worth considering that use higher quality and more durable materials than both of the innerspring mattresses that are listed in the simplified choice list of mattresses. They include Baybed, Nest Bedding, Arizona Premium (mattresses.net), Flexus. and My Green Mattress.
I would keep in mind that a pillowtop is a method of construction and not a specific firmness rating or “feel”. It describes a mattress that includes a separate layer or “topper” in its own compartment which is attached to the main body of the mattress with a recessed edge so that the “pillowtop” layer can act and compress a little bit more independently and would feel a little softer than if the same layer was inside the main body of a mattress. While “most” pillowtops are in a softer range … they come in a very wide range of firmness options and some of them that use firmer materials in the pillow top attachment that would be in a firmer range as well. There are also some “non pillowtop” mattresses that would be softer than some pillowtop mattresses if they use softer materials in the upper layers of the mattress.
If you purchase a mattress that is too firm for you or if you want to “approximate” a pillowtop then you can also add a separate topper which would give you a “sleeping system” that is similar to a pillowtop (if the materials in the topper are similar to the materials in the pillowtop layer in a mattress).
While there is always some risk and uncertainty involved in adding a topper if you haven’t tested the combination in person because the specifics of the mattress itself along with your own body type, sleeping position, and preferences can affect which specific topper would be a suitable choice on any specific mattress … if you do decide to add a separate topper to a mattress then there is more information about choosing a topper in post #2 here and the topper guidelines it links to which along with a conversation with a reliable supplier that can provide you with good information about how their toppers compare to each other or to other toppers they are familiar with that are available on the market can help you use your sleeping experience as a reference point and guideline to help you choose the type, thickness, and firmness for a topper that has the least possible risk and the best chance for success. It also includes a link to a list of some of the better online sources for toppers I’m aware of and a link to the online suppliers that have good exchange/return policies as well.
If a mattress/topper combination is a good “match” for you in terms of "comfort and PPP (Posture and alignment, Pressure relief, and your Personal preferences) then it also has the advantage of being able to replace just the topper without replacing the entire mattress if it softens or breaks down before the upper foam layers in the mattress (which is very likely because the upper layers or a sleeping system tend to soften or break down before the deeper layers) or if your needs or preferences change over time and a topper can also help extend the useful life of the mattress underneath it as well.
Phoenix