I shoot a lot of USPSA and over the last couple years I've been watching different guns checking mostly reliability and what's winning. I shoot a Beretta 92FS, I saw this not to recommend it but to show I don't have a dog in the fight.
What I've noticed is that the M&P seems to be the most reliable, more so then the Glock's or anything else I've seen out there. Those winning 90% or better of our matches are shooting M&Ps.
I've seen too many people (including me) loose time fooling with the safety. My problem is I switch guns too much (Between the 1911 & Beretta) due to shooting different styles of matches. As you know, Beretta's safety goes up, Colts go down.
Production limits the mag to 10 rounds so I have to shoot my Beretta in the unlimited class.
But again, over all I believe the M&P to be the most reliable. Especially in cold weather (like last Sunday's match). I don't understand the glock reliability deal, I just don't see it in matches. Besides most people I know who get serious need to practice a lot, and to make that practice affordable, reload with cast bullets. That lets out the Glock, I wont have a gun I cant shoot cast bullets. The M&P doesn't care.
The Beretta is extremely reliable, the only malfunction I've had with mine in the last 4 years was failure to fire. Seems someone forgot to put a primer in the case. I like the Beretta but its too big to conceal, and I don't know of any 10 round mags for it, so I shoot unclassified. Plus the safety does slow you down.
In short, I vote for the M&P. But to be honest, I don't know much about the CZ.