The buy I bought my bike from had one of those. He said he really liked it. It didn't come with the bike though so I can't comment on it personally.

 

I am nearly 59 years old and the stock seat seems just fine to me even for rides up to 300 miles. Of course the reason may be that I do a lot of bicycling to stay in shape and those seats aren't nearly as cushy. I don't have a problem with stock, but I haven't tried anything else to know any better.