I've ran both the comp and the carry. Go with the carry kit. The comp is far too light, even the carry is a little too light for my tastes.
For any M&P shooter, if you don't have a S&W pro trigger kit you have to have an Apex. First and foremost it gets rid of the horrid trigger over travel issue, and the trigger stops when the round fires. It takes all the grit out, and gives you a nice steady pull that brings you to a perfect wall. Glass break shot, and very positive tactile reset.
I enjoy it, an again, would not run an M&P without one