Out of the box, the trigger feels a bit gritty on the ones that I've handled. However, there are smiths that can give you a clean, crisp 3.5 or 4 pound trigger for less than $100, including shipping. The M&P forum also has links to the directions and photos for doing the job yourself. My .40 S&W MP is being allowed to "wear in" before I do any work to it. The trigger is improving. I repeatedly rang a 10" gong at 50 yards today, shooting offhand. My particular pistol does not have a mag safety or built in lock. It also has the very low profile slide stop release, which is nice for most situations, but it's still a little stiff to operate, and the lack of leverage doesn't help. I could swap out to a larger release, but I doubt I will. Despite having very large hands, I actually prefer the smallest size grip insert. The palm swells on the larger grip inserts just don't feel right, so I'll stick with the relatively flat sided small insert. Some judicious sanding could probably make one of the larger inserts just right for me, but I also share this gun with my wife, so it'll stay as is.
My wife put a fair number or rounds downrange today, and she had no complaints. All in all, the M&P seems to be an excellent gun for the money. I'm thinking about buying more of them, as a matter of fact. Besides defense, mine might also be seeing some use in matches, so the notion of having a back up is appealing.