There are five tomax firmnesses avaliable at the moment. These are hard, regular, soft, very soft, and rich soft. For those who have tried most of these or at least two of these firmnesses, which one is your favorite and why?

Which would you consider the most realistic?
Which would you consider the most stimulating?
Which would you consider the most durable?
Which would you consider the best overall?

Also, I heard that the very soft firmness is the least durable version for some reason. Does anyone else also had bad luck with the very soft firmness?