All other arguments aside, I think one that is being overlooked is simply height. Jefferson was always looked at as legit 4/5 who is principally playing the 5 now at this point of his career. Sully is an undersized 4. And despite the fact that he got some run at the 5 on this year's pathetic squad, no team is dealing for him with the intention of playing him at the 5.
And as we all know, guys who can play the 5 (particularly when they have a good post game) are always going to have more value than undersized 4s.
Agree about the height, and that Big Al could play the four and the 5. I do not agree that Sullinger is an undersized 4. He is an undersized 5 who most of the time guarded the other team's center but when he was guarding the 4 I he had plenty of size.
I personally think that Al's best skill is elite in the NBA, while Sullinger's best skill is simply very good. Sullinger is a very good rebounder, Al is probably the best pure post scorer in the game. Al also didn't have the weight issues and as bad an injury history as Sullinger, I think he was a much better prospect. That being said Kevin Garnett was also much better than Kevin Love.