I have several manufactures' memory foam mattress toppers, and pillows, mostly Serta (from Overstock) and some of the RV matress sets (memory foam) and the trick seems to be, the higher the density, the more bang for your buck. 6 Lb. foam is the high-standard, but comes mostly with the very high-end products. This mattress topper was 4 Lb memory foam, that's why I chose it (probably the densest foam you can get with these mid-priced/low-priced toppers) and it's good. Best night's rest ever with memory foam; now I have it everywhere, in every bedroom in the house! Overstock.com rules!!!