I shot an M&P in 9mm today and was very impressed. I really liked the grip, the trigger was fine, and I could not believe how many rounds the gun holds.
I shoot revolvers mainly, K Frame .38s, but also 1911's. I carry a Makarov. I've never owned a polymer gun and probably never will, but I can understand why people question the need for anything other than a gun like the M&P. Simple, reliable, and accurate. I compared my favorite .45, which I had with me, to the M&P and mine seemed to be a very big, honking, complicated weapon. Honestly, I don't think it would outshoot my 1911, but it would certainly be good enough for anything I would use a gun for.
Enjoy your M&Ps. They sure seem like nice guns.
Chris