Hard to say, when you have a lot of these superstar teams (looking at you UK) it's hard to see how good the players really are because they play supporting roles. Someone like Tom Robinson who is the main feature at Kansas is thriving and looking like a Chris Webber type player if you ask me. Drummond is putting in 7/7 right now, nothing special but he was a late enrollment.
When players only stay for 1 or 2 seasons you can really only go with potential
Drummond is a freak of nature. Biggest, strongest, and fastest player at a top school like Uconn as a freshman. No one can say for sure it will translate to the NBA but he's the most physically gifted big man since Oden and before that Dwight. Much better than Thabeet
Same goes for PJIII.
Barnes, Sullinger are more of the safer picks in this draft having played a couple years as the guy, upside might be a bit lower though. I see them as Luol Deng, and Carlos Boozer types.