I recently bought a Smith and Wesson M&P45. This means that I now have the M&P40, M&P Shield, and now the M&P 45. I have to admit that I am greatly enamored of the entire M&P line.
I have (or have had) a collection of various handguns from different manufacturers:
Third Generation Smith and Wesson 45’s: The 4506, 4516.
Sig Sauers: P220, P226, P229
Kimbers (since sold) Pro Carry II, Crimson Ultra Carry II, and Custom
Glocks: 22, 19, 26, 27
and so far, I have to say that I think the M&P is the best that I have had so far. As long as you change out the trigger for the Apex trigger, this series is accurate, reliable, feels good in the hand, and seems to eat whatever you put into it. It is easy to repair and modify yourself, and I think that Smith as a real hit with the M&P series.
The pistol that I am currently carrying is the M&P40 with a 9mm conversion barrel. I have 18 rounds of 115 grain 9mm+P Corbon ammunition ready to go, and with a muzzle energy of over 400 foot-pounds, I think that this makes a fine defensive piece.