My problem with Kuz is he's not really strong. He can easily be pushed around. The part about work eithic is true, but he may just never be able to battle physically in the NBA.
I'd sign him, sure, but no more than $4.million per. He's long and indeed defensive oriented. And he's learning under Bogut, so he could bring some of those philosophies defensively, but don't expect toughness from Kuz. That's pretty much what's holding him back.