First, sleeping on Sleep Better 2 Inch Elastic Mattress is a high quality sleep. Perfect amount of support in everything you put into it. I put a 2 "on a futon toppper eight years you may feel that the image is there and it was like sleeping in the bed of my parents $ 5500.
* Two * things you need to know the density is. Not expensive £ 3, £ 4 and £ 5 is average premium. £ 2 has no "memory" for the support, thus very little. Easy to grow and is essentially instantly.
Secondly, there ... aging. I'm in my second Serta Topper 4 pounds, both were great until about 8 months before I realized that there is less "memory". At 11 months, it feels like two pounds of foam that does not offer much support, but rather foam you would think that wrapping things. I compared the areas that can be compressed and often unused corners (near the foot) and there were some, but very little difference. It seems that the use is not a factor, but age. I stuck a glass object on it and measure the depth of the wreck and measure the time it took to download, but it was essentially instantaneous compared to when it was new when it sank in the quicksand that someone (I can say I'm an engineer ...).
Thus, 2 Memory Foam Mattress Topper ... Impressive ... but has a shelf life. Something to keep in mind when considering to go foam. I do not know if the mattresses have the same problem, but if I had to guess, it would probably be less affected.