I wanted a "firm" mattress. I had a big, puffy, pillowtop mattress, but the older I got, the more I needed a firmer mattress. I really like this new memory foam mattress. It is firm (as stated in its description), and I have had a good sleep every night I've had it. I have not woke up "hot" like some people have with memory foam mattresses.
I had a coupon for an additional discount, so this mattress was super affordable. Another website that has mattresses on sale (rhymes with "coupon") didn't even have an 8" memory foam mattress for the price I paid for this one.
I've only had this for a few weeks, so I cannot comment on the wear, sagging of memory foam mattresses, or anything else, but so far so good!