In college, Sully routinely ate up taller players unless they were very good, savvy defenders. Sully is very crafty and that hip-bump, twist and under move is really hard for a lot of big men who are used to playing over the top to stop. Basically, Sully would just go under & around them with that flip layup.
Teams that have shut Sully down have usually done so with double-teams, swarming him. This is not likely to happen to Sully if he has KG on the court. But he is smart and as we saw in the SL, even if he can't get his shot off in those double-team situations, he knows how to turn that situation into free throws.
Sully could quickly be our second-best player, behind Pierce, at drawing fouls.
I'm not at all worried about Sully becoming an NBA-caliber scorer. The only real question is how he'll fit in defensively. I think if he's on the court with a mobile, long defensive big man like KG he should be just fine - Sully should definitely be able to play the role of strong post / weak side help defender behind KG. The bigger question is how well he'll fit with our other bigs. Fab, of all folks, might be his next most complementary defensive partner in the long run (after KG). I try to envision how Sully will fit defensively with Bass or Wilcox and I just don't see it. Not enough horizontal defense there. We can probably get away with putting him out there with Darko or Collins, against deep bench units and just see how it develops. I'd want some fast, good perimeter defenders surrounding them though.