I got my M&P Pro in Feb of this year.
It shot low then but it I did not have much time to work with it.
I finally took it out in May or June and sure enough it shot 6" low at 25 yards 4" low at 15.
Called Smith they sent me a label and I sent it back.
They replaced the barrel and it still shot low.
Accurate but low.
I think I figured out my problem last night, I was holding the fiber optic where I usually do on my revolvers which was right at the bottom of the rear sight. If I ingore the F/O and use the corners of the sight at the top of the rear sight it is dead on.
I am going to work on this a bit then if this proves out over a few hundred rounds i will replace the front sight