Though the RSD design looks good, from what I can see in the pictures here, there doesn't seem to be much cushion for a bit softer feel. I've a Corbin currently and it has overtime become akin to sitting on a plank of wood and the stock seat in comparision feels way more comfortable. I feel sore after a 30 mins ride with Corbin. I'm planning to get some gel in the corbin for some relief.
Hopefully RSD version has better cushion/foam right out of the box than Corbin.