I rode on Neiharts for about 400 miles one day when he graciously let me borrow it while my stock was off getting replaced at Russell Seats. Of course, his ass is thinner and bonier than than mine. For the first 300 miles, it was nice. After 350, I had some lower back pain. The Russell lets me do at least 600 miles without pain. That seat pan is much more comfier for my bum.
If you ride aggressively, Rich's might be the better option as you can hang a bit better off of it.