And... what is best: visco, latex, spring, technical foams, HR foam, Gel Foam...?
There is no any ideal material, each person has its own needs for sleep and that is what makes the best combination. Ideally, unless you have a clear preferences on the material you need, is better not to go out and look for technologies. It's simple, what we seek is a product that allows us to sleep well. The technology is the means to get a good rest but first you must know what comfort is best for us. Go to a retailer, try and trust your feelings. That is what really matters.