1st: I test rode a 2007 R3 with get seat, MAJOR PAIN after 10mins riding!
2nd I Test rode another 2007 R3 with stock seat (touring), much better but still some pain after 35mins.
3rd I now bought an 06 R3 with Seat & pillion, much better than the above. I can now ride about an hour before major pain. Yesterday I rode 3 1/2 hours, some pain but was bearable.
About Corbin being hard. I also own a Kawasaki Vulcan 1500, when I first got it I couldn't ride more than 20 minutes. I bought a Mustang seat (very hard seat!) And at first it just doesn't feel right. But somehow your weight is spread evenly and I can ride 5 hours straight before starting to feel any stiffness.
Bottom line hard doesn't mean uncomfortable. It's the shape of it that's important.