Hi sicko,
Unfortunately the major players in the industry (major brands, mass market outlets, and chain stores) have a vested interest in making meaningful comparisons for value very difficult if not impossible. The only way to make meaningful comparisons is to know the materials in every layer of a mattress and the major brands don’t release this. These guidelines may help you avoid most of the worst choices and help you spend much more time focusing on the better ones. In essence it boils down to only shopping at outlets, mainly factory direct manufacturers or sleep shops who selll alternative or local brands that they have a closer relationship with and who are knowledgeable about the materials that are used in mattresses, completely transparent about every layer, and good at helping you make good choices based on your needs and preferences. These outlets are much less common in the industry.
The iComfort lineup is typical of major brands and have poor value IMO. There is an analysis of the lineup in post #11 here.
I can certainly understand and agree with the spirit behind this but it’s very difficult to predict how long any mattress will last for any particular person because there are so many variables that have nothing to do with the materials in the mattress. Ultimately though … latex is by far the most durable of the foams and high quality 5 lb or higher memory foam and HR polyfoam (2.5 lb density high performance polyfoam) are also much longer lasting than other materials. In addition to density which is the most important spec that determines the durability of a polyfoam or a memory foam … how close to the top of the mattress it is, the softness of the foam, and how much and the frequency of the mechanical compression it is subject to (heavier weights and more “active” sleepers will wear out a foam faster) can all affect durability. There’s always a lot to be said for a mattress with a zip cover that has layers that can be replaced if the top layers wear out too soon or the use of a topper on a firmer mattress which can also be replaced as needed without replacing the entire mattress. A purchase from a local manufacturer can also be helpful as they will usually repair a mattress for a very reasonable charge if a layer wears out.
Washington DC doesn’t have a lot of great choices but the better ones are listed in post #2 here. In addition this thread may also be helpful.
It’s always fairly risky to make a purchase online from an outlet that knows nothing about mattresses because each mattress can feel very different to different people with different heights, weights, body shapes, and sleeping positions. In addition to this … small changes in a mattress (such as a layer that is an inch thicker than another) can make a big difference in how a mattress performs and feels. Even different versions of memory foam made by different foam manufacturers and used by the mattress manufacturer can feel very different from each other so knowing what one version of memory foam is like doesn’t mean another one will feel the same.
The good news though is that with places like costco you can “roll the dice” on a blind purchase and if your number doesn’t come up (and you don’t like the mattress) then they offer a full refund.
I would never consider a 3 lb memory foam mattress for anyone except for occasional use in a guest bedroom of by someone that doesn’t mind possibly throwing away the mattress in a very short time (in some cases months). Warranties don’'t cover foam softening or a mattress wearing out so there would be no warranty recourse in almost all cases if the foam became too soft or wore out.
I would follow the guidelines in post #10 here for any memory foam purchase.
That would exclude any memory foam purchase where you didn’t know the density of the memory foam and the polyfoam suppprt layers (although most of these would be OK) or that wasn’t tested for certain chemicals or VOC’s. That means that for the Novaform (which is made by Sleep Innovations which is CertiPur certified) I would want to know the density of the foam layers before I considered it. For Sleep Science which has better looking specs, I would want to know the source of their foam (it’s Chinese) so I could make sure they’re CertiPur certified (which I don’t believe they are and they won’t tell you if you call them) and as I mentioned for bedinabox they use foam that is too poor quality to consider.
A few better online memory foam outlets and manufacturers are listed in post #12 here
If I was going to buy a low budget memory foam mattress in the 4 lb range from a box store I would probably favor the Aerus mattresses at Walmart (except the 3 lb version) or at Sams Club (again except the 3 lb version) over most other options but again it’s important that you know the construction of the mattress would be suitable for you or at least be willing to take a chance because of the refund policy.
Hope that helps a bit.
Phoenix