I think that, like PVP, CAD is good when he's making jokes about gaming without trying to be deep and serious. Jokes about Ethan being ridonkulous also work so long as they aren't juxtaposed too closely to strips where we're supposed to actually respect him as a human being for some reason.
Also, one of the few things I DO have a vested interest in CAD is about seeing what's behind that goddamn door. I think I'd enjoy the strip a lot more if Scott and Ted were used more often.