The thing is that he needs a screen - not going to beat his man straight-up off the dribble very often. BUT, if you're a good passer and you can shoot to kill if your man goes under, you can make that work. Bigger problem is going to be finishing at the rim; he'll have to develop a better finesse game if he ever wants that to work out, lol.
I've seen him defend pretty solid NBA scorers well on a number of occasions, and I've also seen him look like total ass on that side of the ball. I think a lot of it is mental for him...obviously a "flow" player.