Hi Fyrurm,
The first place to start your research is post #1 here which has the basic information, steps, and guidelines you will need to make the best possible choices. It also includes a link to some of the better online memory foam options I’m aware of.
You can read a bit more of my thoughts about Bedinabox in post #2 here. Reviews can also be very misleading in terms of knowing the quality or value of a mattress and are among the worst ways to choose a mattress (you can read more about reviews in post #13 here).
The upper layers of a mattress are the most important part of durability and this is where higher quality materials are most important. The deeper support layers are not usually the weak link of a mattress. You can also read more about the guidelines I would use when choosing a memory foam mattress (including gel memory foam) in post #10 here and the minimum density I would tend to consider is around 4 lbs or higher. Their memory foam doesn’t meet these guidelines even though their base layers are high quality.
Memory foam comes in a range from about 1.5 lbs to 8 lbs or so and and has a different density/quality range than polyfoam which is usually anywhere from under 1.0 lbs (very low quality) to about 3 lbs (very high quality). The range of “better quality” polyfoam typically starts at about 1.8 lbs and this or higher is what I would look for unless you are in a lower budget range where as low as 1.5 lbs may be suitable in some applications or designs … particularly if the materials on top of the mattress that are more likely to soften and break down are higher quality and “protect” the lower density foam below it.
So their base polyfoam is 2.4 lbs and good quality but this is a lesser part of the overall durability of a mattress. It’s the density of their memory foam / gel memory foam that I would want to confirm was in the range of 4 lbs or higher before I considered them.
Phoenix