We to have the genuine tempur mattress and its the best thing i have ever bought, my friend however bought a topper and is very dissapointed with it, says it makes little difference.I would imagine the effectivness of the topper directly relates the how bad the matteress is that your putting it on to, hence the varying replys,the topper can only do so much to improve the quality of what its put on top of, but if its not too expensive its probably worth a try, cheaper than new materess :-)