Hi azrael,
[quote]Out of the choices I listed before, we have narrowed it down to the Serta iComfort Savant and the TempurPedic Cloud Supreme Breeze. If there are any better options sold by Ashley I would be grateful for the recommendation.
The information I can find about the densities of the mattresses indicate that the iComfort Savant has 2" memory foam (3lb), 1" regular foam (1.2 pcf), .75" regular foam (this should be the Everfeel Technology Foam but I am unable to locate a density), 1.5" gel memory foam (4lb), over a 6" foam base (1.5 lb). The TempurPedic Cloud Supreme Breeze has 2" memory foam (4.1 lbs), 2" memory foam (5.3 lbs), and a base of 7" regular foam (2.2 lb). There is a $2,000 price difference between the two.[/quote]
As you can see in the foam quality/density guidelines here … like most of the Serta mattresses I would avoid the Savant completely because of the lower quality/density materials inside it that I would consider to be a weak link in the mattress. Anything more than “about an inch or so” of lower quality/density comfort layers would be very risky in terms of durability and 3 lb memory foam and 1.2 lb polyfoam are both low quality materials.
The Tempurpedic Cloud Supreme Breeze doesn’t contain any lower quality materials or have any obvious weak links in the design relative to your weight ranges so they would be a much more durable choice although Tempurpedic mattresses are significantly overpriced compared to other mattresses that use similar quality/density materials and sell in much lower budget ranges.
[quote]Husband feels the Cloud Supreme Breeze is a softer bed than the iComfort and prefers the iComfort. I feel the iComfort is softer than the Cloud Supreme Breeze. To me, I feel like I “sink” more into the iComfort wheras the TempurPedic feels more supportive. Husband and I find both mattresses comfortable and can’t decide between the two.
I want to pick the option that will be the most comfortable and last the longest. I can’t help but note that for the price of the TempurPedic, I could buy two iComforts but this is a moot point if the TempurPedic doesn’t last twice as long as one iComfort.[/quote]
There is more about the most important parts of the “value” of a mattress purchase (or exchange) in post #13 here that can help you make more meaningful quality/value comparisons between mattresses.
The most important part of the value of a mattress is PPP (Posture and alignment, Pressure relief, and Personal preferences) which is all about how well you are likely to sleep on the mattress. I can’t help with this 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 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 would be the best “match” for you in terms of PPP or how a mattress will “feel” to you based on specs (either yours or a mattress) 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).
The next most important part of the value of a mattress purchase is the quality and durability of the materials which is all about how long you will sleep well before you need to replace the mattress because it is no longer providing the comfort or support that is suitable for you.
While it’s not possible to quantify how long any mattress will last for any particular person, if a mattress is well inside a suitable comfort/support range and isn’t close to the edge of being too soft when it is new (see post #2 here) and meets the minimum quality specs that are suggested in the guidelines here then it would be reasonable to expect a useful lifetime in the range of 7 - 10 years and with higher quality and more durable materials that are well above the minimum guidelines like latex or higher density memory foam or polyfoam (in the comfort layers especially) it would likely be in the higher end of the range or sometimes even longer.
If a mattress doesn’t meet the minimum guidelines then in some cases it may only last you for a year or two before foam softening and breakdown takes you outside the comfort/support range that is suitable for you and you would need to buy a new mattress. I would also keep in mind that warranties don’t have any relationship to the durability or useful life of a mattress and longer warranties are more about marketing than anything else (see post #174 here).
The last part of the “value” of a mattress is how a mattress compares to the other mattresses you are considering based on all the other parts of your personal value equation that are most important to you.
[quote]The iComfort website offers a 120 day in-home trial and the TempurPedic website offers a 90 day in-home trial. The manager at Ashley Furniture said that they will not honor the in-home trials because Ashley will lose money if the mattresses are returned since they can’t resell the mattress, essentially we will be “stuck” with whichever we choose 
If there are any better options sold by Ashley I would be grateful for the recommendation.[/quote]
I don’t have any specific recommendations because your own careful testing is the most reliable way to know whether a mattress is a good match for you in terms of PPP and I would need to know the specifics of the materials inside any of the mattresses you are considering (see this article) to be able to make any meaningful comments about them in terms of durability. There really aren’t any mattresses that are sold at Ashley that I would normally suggest considering so you are really in a position that you will need to choose the best out of some rather undesirable options.
It also seems that you are following the first strategy that is described in the link in my previous reply and it may be worth considering the second strategy as well. One of the advantages of buying a firmer mattress that minimizes the use of lower quality or unknown foam materials and then adding a higher quality topper to provide the additional “comfort” and pressure relief you need is that a topper can extend the useful life of the mattress underneath it and if a topper softens or breaks down before the deeper layers in the mattress (which is likely) then you can replace just the topper without having to replace the entire mattress. You can also change the topper if your needs and preferences change down the road also without replacing the entire mattress.
The biggest “risk” to this approach is choosing a topper that is suitable for both you and the mattress you are using it on but there is more information about how to choose a topper in post #2 here and the topper guidelines it links to that 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 as well.
Phoenix