I've had this conversation with a couple of different people and it really seems to come down to this RE: eye test. CJ "LOOKS" like he cares. By that I mean, if he gets caught on a screen he's scrambling to get back, grabbing, clawing, chasing- anything he can do to recover. Couple that with CJ gambling a bit more and poking a few more steals away and VOILA?! you've got what looks to be solid defense, coupled with effort- what more could you want? Meanwhile, we've all seen Dame get hung on a screen and give the IDAF look and become a bystander the rest of the play. I HATE that, but I can almost understand it. That sounds weird I know, but I'll go more into that later. What I've seen in the past week against some of the most dynamic PGs in the league- and some of the best screen setters, Gasol & Randolph, Jordan, Bogut & Green, Adams & Kanter- Dame has been unbelievably good about not getting caught and not trailing/chasing the play from behind- but instead moving before the pick is there to 1) offset the effectiveness of the pick 2) attempt to draw an offensive foul (which he did 3 times in the course of 4 games- that makes a difference!)
Beyond that- the metrics have Dame improving in the PnR game every year- although his first 2 years were some of the worst defense I've ever seen from a All Star level guard. As for CJ- he has the skills necessary to be at least a net even defender. His issues stem from overextending on rotations, going under screens when he should go over, and getting caught up in off ball action and sealed on the backside of a play.
Does that make sense?