Ball's defense looked really good out there. We'll need to see him against better scoring PGs, but he was able to move his feet, stay in front, and fight through screens. I think he might get beat 1 on 1 a lot by the quicker guards, but it seems like his big frame and wingspan allows for good recover D.
The one thing I like about Ball is that he doesn't assist hunt. Guys like Wall, Rondo, and Rubio are guys who tend to do this a lot. He's playing within their offense and making necessary passes. However, his big problem will ultimately come down to how effectively he can break down the 1/2 court defense. If he can fully run 1/2 court sets for his teammates. He does a good job at pushing and nulling pace, but the NBA always comes down to 1/2 court offense. He needs to be more of an aggressive scorer because often times, he's just caught floating out there.
His debut was poor for the #2 pick, but he did flash a lot of positive things.