For me, Sully's ceiling is David West. That's not HOF material, but that's not chopped liver either.
The criticism of Sully's 3-point shooting kind of annoys me. The coaching staff wants him to take those shots, and has been encouraging him to do so all season. They are using it to develop a part of his game that they think will benefit him/the team in the future. This is a throw away year, what better time to do it? It isn't as if he's Antoine Walker chucking up 3's until the backboards shatter.
I find Sully's post defense to be questionable at times, but I want to see how he fairs when there are players on the team that can protect the rim a little bit. Right now, Kris Humphries and Brandon Bass are the leading shot blockers on the team - that's pathetic. The team is built to fail on the defensive end of the floor.