He's definitely a difference maker. He makes a huge difference, the team is way worse with him than anyone else. He's probably the worst defender on the team, I don't know why everyone says he's a good defender. He gets blown by more often and more easily than anyone I've ever seen.
McCaw is a worse option to start at SG than: Powell, Miller, Thomas, Davis II.
You are right that for some reason he seems to have the faith of the organization though. I maintain that that doesn't mean his being available to be overplayed because of that faith would have been a good thing for the Raptors.
You're basing your assessment on two games? On his 28 total games as a Raptor that total 440 minutes? As you like to say, "sample size". For a guy who likes stats, the advanced stats say he's an above-average defender. Offensively, he clearly has a ways to go. He's athletic, smart, and a good defender, but he hasn't been able to a) stay healthy; b) find his role in the offence; and c) play with confidence.