Hi jperiod,
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. There are just 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”, firmness, or PPP 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 reliable 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).
I’m not sure what you’ve read since you found the site but just in case you haven’t read it yet … the first place to start your research is the mattress shopping tutorial here which includes all the basic information, steps, and guidelines that can help you make the best possible choice … and perhaps more importantly know how and why to avoid the worst ones.
Two of the most important links in the tutorial that I would especially make sure you’ve read are post #2 here which has more about the different ways to choose a suitable mattress (either locally or online) that is the best “match” for you in terms of “comfort”, firmness, and PPP (Posture and alignment, Pressure relief, and your own Personal preferences) that can help you assess and minimize the risks of making a choice that doesn’t turn out as well as you hoped for and post #13 here which has more about the most important parts of the “value” of a mattress purchase 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 all the parts of your personal value equation that are most important to you.
While nothing has a 100% success rate … with a local purchase for the majority of people … careful testing using the guidelines in the tutorial (rather than just testing for the more subjective “comfort” of a mattress which often won’t predict how well you will sleep on a mattress or how it will “feel” when you sleep on it at home) along with some good guidance from a knowledgeable and experienced retailer or manufacturer will usually result in a mattress choice that is well inside a suitable comfort/support range and will generally be “close enough” so that if any fine tuning is necessary it would be relatively minor and involve different mattress pads, sheets, mattress protectors, or perhaps even a topper if a mattress is too firm (see post #4 here and post #10 here).
Again … your own local testing would be a much more reliable way to assess whether any mattress is a suitable choice for you in terms of comfort, firmness, and PPP.
There is more about the pros and cons of a thinner and more stretchy knit cover and a wool quilted cover in post #6 here.
Both Arizona Premium and SleepEZ sell component mattress that give you the option to choose between 100% natural Talalay and blended Talalay. The choice between different types and blends of latex is more of a preference and budget choice rather than a “better/worse” choice and any type or blend of latex is a durable material relative to other types of foam materials. There is more about the different types and blends of latex in post #6 here and more about how Dunlop compares to Talalay in general in post #7 here but the best way to know which type or blend of latex you tend to prefer will be based on your own testing and/or your own personal experience.
Blended Talalay is more common than 100% natural Talalay because it’s generally less costly and is just as “safe”, just as durable (or in some cases more durable) and feels very similar to 100% natural Talalay.
Again … the best way to know whether any mattress design is a good match for you would be based on your own careful testing but 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 thickness of a mattress or the number of layers or the thickness of any individual layers inside it is really just a side effect of the design and the design goals of a mattress and is also only one of many variables that can affect the feel and performance of a mattress relative to any particular person and by itself isn’t particularly meaningful (see post #2 here). In some cases higher weight ranges (or a higher BMI) will sometimes do better with a mattress that is thicker than lower weight ranges or a lower BMI (see post #14 here for more about the effect of thickness) but even this depends more on the specific design and combination of materials in the mattress and on how well your testing or personal experience indicates the mattress “as a whole” matches your specific needs and preferences in terms of comfort, firmness, and PPP than it does on just the thickness itself.
There are also some comments about the pros and cons of a component mattress with a zip cover where you can choose the type and firmness of each layer vs a “finished mattresses” that has glued layers in post #15 here and post #2 here.
I certainly wouldn’t go by the opinions of a younger child about which mattress would be suitable or “comfortable” for them because they will tend to choose based on all the wrong criteria (just like they would probably make poor food choices if what they ate was based on their preferences as well).
Post #2 here and the topics it links to have more information about mattresses and children and “safe” materials including a link to some general guidelines for children in post #2 here. It also includes a number of links to the better forum posts and topics about mattress and children as well which have more information about many good options for children which are worth considering.
For younger children any mattress that uses materials that are “durable enough” that you would also consider to be “safe enough” and are in a medium to medium firm range would generally be a suitable choice for a child. The choice between different mattresses that meet these criteria would really be more of a budget and preference choice than a “better/worse” choice.
I would keep in mind that a mattress that would be “comfortable” for most adults would likely be too soft to be suitable for a child. You can also add a softer topper to any firmer childrens’ mattress when they get older and develop more adult proportions if and when they need a softer comfort layer in their “sleeping system”.
You’ve probably already seen this already but just in case you haven’t … the better options and possibilities I’m aware of in and around the Phoenix area (subject to making sure that any mattress you are considering meets the quality/value guidelines I linked earlier in this reply) are listed in post #4 here.
You are very fortunate to live where you do since several of the manufacturing members of this site are based there which gives you the chance to test mattresses in person that most of the rest of the members that live in other areas of the country can only order online without being able to test them first.
Phoenix