My wife and I have the $2000 "big-name-brand" memory foam mattress that our kids love (and so do we!). I ordered one of these 9" thick twin varieties in "soft" for our oldest daughter -- it is an excellent mattress. The 9" thick is what you want -- much like a conventional type mattress that the sheets will fit on. I like the soft variety as it is a bit softer than my wildly expensive memory foam mattress (I would guess mine would translate into a medium firmness by this vendor). This is the exact same memory foam stuff you can spend a heck of a lot more on from what I can tell. My daughter loves it so much I bought two more of these (in soft) for my other two kids. Also, my name brand memory foam mattress out-gassed for month (wasn't a real big deal, BTW) but this one had no odor I could detect.