I started in IPSC with the M&P Pro, used it for about two seasons, then got a CZ Shadow and have used that since. The shadow is likely the more competitive pistol, but my friend has an M&P and still uses it for IPSC and still manages to beat me at least half the time. At our level, it's more skill (or lack of) than the equipment.
If you haven't done the black badge course yet, and aren't especially familiar with a particular type of pistol action (like a DA/SA action) then a striker-fired pistol like the M&P is much easier to learn on. This is because you won't have to fiddle with the safety. There is a lot to learn at the black badge if you're a new shooter (and apologies if you're not) and I found the less you have to focus on working the mechanics of the pistol, the more you can concentrate on the skills involved (safe holster use, movement, etc).
With a CZ you're either going to have to manipulate the safety off and on frequently, or learn to lower the hammer with a round in the chamber (probably not something you're going to want to do if you aren't extremely comfortable with the pistol).
Now if you want to do accuracy style target shooting, the CZ will give you tighter groups (depending on the skill of the shooter, of course). The M&P is not known for it's tight groups, although apparently that issue may be better now, with later models having the bugs ironed out.
Or just do like I did, and buy both