Gary, if you can get your hands on a copy of Consumer Reports from last May, it will offer some enlightenment. Some people are "allergic" to latex, so that may be a concern when choosing. Tests indicated latex foam may offer more stabilization, i.e.- resistance to bounciness. The Costco-offered Novaform at $900 had the best value rating among memory foam or latex types.
The biggest controversy in those types is whether they induce too much heat retention and sweating and the accompanying discomfort. Some now claim their gel foam combos breath better, but Consumer Reports questioned that contention. Also, since memory foam mattresses conform to your body, they can resist your movement. I don't like excess body heat retention (most guys like to sleep cooler than women), and I tend to change position a lot before I finally doze off; so I've resisted buying a memory foam mattress despite acquaintances who swear by them. Manufacturers counter that because foam conforms to your body so comfortably, you will fall asleep before needing to change body position; yeah, right.
Right off the bat when we got our new coach in Bend, the first night in the BCS parking lot was not good; the factory mattress was way too firm for either of us - might as well have slept on the floor. So the next day off we went to Costco and got a foam/down topper, whaich is flippable as per the season of the year. It is better than the factory mattress for sure, though I can get a tad warm on the backside sometimes, but I sure love my first night back at home after a long RV trip; our plush $1800 Serta innerspring is vastly more comfortable. Admittedly, the Novaform full mattress may be a far different animal than the topper.
Many of today's innerspring mattresses use some form of memory foam and or gel or latex foam in their plush tops.
Try to find the May Consumer Reports, perhaps online or at a library.
-Joel
