Yeah, I watched every Syracuse game with Joseph during my four years at Syracuse.
He's capable of guarding 2's. I wouldn't say that's his strong suit, and he could struggle against smaller, quicker 2's, but he's certainly capable. He isn't lacking in athleticism.
I think he has the versatility to guard longer 2's, all 3's, and small 4's at the next level. He's going to have to adjust from the 2-3 zone at Syracuse, but I think he can develop into a nice team and perimeter defender in the NBA.