I put an Apex sear in my M&P 9L a couple of days ago and I have to say I'm really impressed. The trigger wasn't horrible before, but when I would dry fire I noticed the front sight would do a little dance every time the trigger broke. The trigger had some creep right before it would break, and it kind of stacked somewhat. I'm not very good with a handgun, so I don't have the best trigger control. After putting in the sear and polishing the trigger bar & striker the front sight doesn't move a bit when I dry fire. The trigger now is quite a bit lighter, with a crisp break and no creep once the initial stage is taken up. It's comparable to a really nice 2 stage trigger on a service rifle. I know that sounds kind of weird, but that's the best way I can describe it.
I'm sure someone who's a better shot with a pistol would have been able to master the factory trigger, but for someone like me I think this is going to make a huge difference. I can't wait to take it out this weekend and see how much better I shoot. If anyone has an M&P I would highly recommend this upgrade. It's a little on the pricey side, but I think it's well worth it.