Long story short I couldn't hit squat with the M&P 9MM Pro Series gun..even with the APEX Competion trigger parts in it. It was really discouraging. I'm not a marksman but have always been able to group most anything I shot.
I got my son out to the range...a die hard Glock guy that competes on a regular basis. He picked it up...shot it 5 times and put 5 rounds within 1" of each other.
He made me aware of the sight picture pointed out here and after months of practice I now have two Pro Series 9's that I can consistanty group within 2" at 25 yards.