I watched him a bit vs. LA and wasn't impressed at all. Mind you, it's a summer league, the guards hardly passed the ball on offence, but he was beat on defence a couple of times and he was consistently out of position for defensive rebounds.
He is huge, though, and very mobile. The key for him would be a lot of practice against real NBA players, and spending some time with JO and Bargs
in Vegas should do wonders.