There was an instructor on a gun blog, I can't quite remember, who did say he had more issues with CZs than other mainline brands, and one example was a class with 3 and a clone. Interesting discussion in the comments.
I've heard a ton of positive about them though, too, so...who knows.
Ah, here we go, it was ToddG at pistol-training. I don't know his credentials.
http://pistol-training.com/archives/3218