I've been running the same Corbeau Ultra SS Wide seats in my Jeep for ~10 years. 6'4", 220lbs and they fit me great. I've sat in other seats but nothing has made me think I needed to spend the money to replace my Ultras. I did replace the covers a couple years ago and went from fabric (black that had faded to a nice blue) to vinyl. I also added the bilge fittings like were posted on the previous page so they don't hold water.
I've got disk degeneration issues and had back surgery in 2012. I can ride all day with no issues in this seat. I haven't spent more than a few mins in any other seat, but I don't see how it can get better than being comfortable with no pain.
If I was buying new seats, the Corbeau XPs would be at the top of my list, but I'd certainly shop around to see what other options were available.