Is the riding position just better or is the seat itself more comfortable too? I'm 6'4"/265 and I've been looking to get a new seat on my Ultra that's easier on my butt.

 

Pretty sure the pre-08 tallboy moved you back slightly and up.

The POST 08 tallboy moves you back and down a bit (its just not as thickly padded as the stock seat)

There have been some changes to some of the seats since 08 even though the name is the same. ex: the sundowner passenger section got 2" wider in 08

 

SouthGAHog,
I find the seat more comfortable than the stock POS the 2009 Ultra came with. The nose is narrower and doesn't feel like it's pushing your thighs out, thus my legs were not as sore and I could "hug" the bike going around curves, corners, etc. I only have about 100 miles on the seat but much more comfortable for me..
Also +1 on what WWIflyingAce posted.....he is right on...
I'd find a dealer that has one in stock and let them do what they let me do, test ride it. Told me that if I bought it, took it home and tried to return it, NO WAY as it would be considered USED !!...go figure.

Good luck..ride safe.