I have the Apex FSS trigger kit in my M&P45 and love it. It really improved my groups. When I was shooting a lot last spring (worked at a gun range), I had no issue shooting poppers at 60 yards with it. We built some walls out of railroad ties for our 3-gun courses, and if I used the wall as a rest, I could dang near hit those poppers every time out to around 110 yards. Standing with no rest, I was probably 5/10 on the 90-110 yard poppers. Before I put that trigger in I had a much harder time shooting that gun well.
I also installed most of it myself, and it was fairly easy. The only thing I had the local smith do for me was drift the rear sight off. I didn't have a bronze punch and it was recommended, IIRC.