TP
I don't get the impression people really understand Sully's potential. He had a 20/20 game against a top front court and now people are calling him fat. He's a throwback guy. Watch him be a top PF in the league in a year or two. He's that promising.
Sullinger is my favorite player currently on the Celtics.
You're right that he's an old school player. I like that about him. I think that kind of lowers his ceiling a bit, though. In today's league, I don't think a player with Sully's physical profile can be a top big man unless he's got the ability to be an isolation scorer on the perimeter and down low. Sully's got some range, but I don't think he's gonna be Love, Dirk, or even Aldridge.
I view Sullinger as a potential Carlos Boozer / David West type, which is nothing to look down on, if you ask me. Especially when you consider that he has three point range (albeit hitting those shots at a Sheed-like rate at the moment).
I think Sullinger can be the #2 or #3 player on a really good Celtics team, depending on how good the #1 is. That's great, because it means the Celtics are much closer to completing the rebuild than they easily could have been. Imagine if Orlando had taken Sullinger and we had ended up with Andrew Nicholson, for example.