These days memory foam is all the rage and I thought about getting a topper made out of it. I soon discovered many things against it:they are moderately expensive, they might get hot, they might exhale noxious fumes and, by my own experience -by testing one in a showroom- have not that great support. Browsing the net for alternatives, I came across the Pure Green latex topper from Sleep on Latex and after searching a bit more, bought one for $149.
I got the 2 inch model in the twin size and have been sleeping on it for three months now. For delivery it was wrapped in a very tight roll made out of a plastic bag and shrinkwrap which was a bit difficult to cut through. When freed, the topper soon expanded to its full length. The first thing I did before use was to measure it and have it made a custom cover because I was planning in using it for many years and would like it from getting soiled. Apparently there are sized covers that can accommodate the topper and a bed cushion, but I didn't look into them.
The cover made and the topper placed I found a few positives and a couple of negatives. First, it was more expensive than comparable memory foam toppers, but a bargain compared with what cushions cost these days, never mind if they're made out of exotic materials. The topper is not hot at all and, while soft, gives a good support to my whole body. So far, I have found it as firm as in the first night. When newly opened, it does smell, but this has both lessened with time and was not very strong to start with.
There is no way you could fold it for storage, but you could try rolling it and tucking it somewhere when not in use. Be sure to save the bag it came in. If not secured to the mattress while in use, the topper has the tendency of shifting out of position. Not a huge problem as one adult can reset it without too much hassle. I don't see it slipping all the way off.
My sore spots, and this is the part you might be the most interested in, did get some relief, but didn't totally alleviate for good. I would say my discomfort lessened to about 50%. However, I believe that giving it a few more months will let these spots to heal some more. Having said this, I don't believe that getting the thicker, 3 incher, would give me more benefit. I would say that the 2 inch would be best for most, unless the sleeper is overweight (I'm about 175 pounds). The harder models might have something to them, but I am in no position to recommend them at this point since I have not tried them. Soft on medium mattress worked for me.
Overall, even though it didn't completely solve my problem, the topper provided considerable benefit. For the price, I don't believe one can do much better.