The most important recommendation is to make sure that the mattress is by a good company that uses all NEW material. Sounds like an obvious thing but I just saw a report on mattresses that were refurbished being sold as new. YUCK!!! My son is due to buy a new mattress and said he will not buy the pillow top kind again. It was great for a while but you can't flip it if it developes a sag. I buy a good quality firm mattress and purchase the foam topper for it. I need the firm support for my back but my poor little boney joints need the foam padding.