I'm betting that the CZ will be more accurate, by a significant margin. I am only an average marksman, and I can empty a magazine, unsupported, into a paper plate at 25 yards nearly every time...something I cannot always do with a 4" handgun, much less a 3".
Having said that, however, I had some feed problems with mine, early on, and had to send it back to the factory for a serious 'fluff and buff,' before it would reliably feed hollow point ammo. Still, it's a great little pistol, and one of my all time favorites to shoot. Supposedly, the feed problems have been corrected. If that is true, the RAMI is one of the all-time great compacts, in my opinion.
The M&P is well liked by those who own them, too. The only negative I have heard was from Gun Test magazine, whose M&P compact test gun would only shoot 4" groups off of a rest, even after sending it back to the factory.