I just wanted to mention this. Yesterday I tried to take the 45 out it's micro companion, my new 9 compact, to the range. There was at least 2-3 feet on each side of the poorly plowed 2 lane, now a 1 lane, road. I ended up just parking on the forest road and walking a few yards out toward the pistol range in the 2+ feet of snow just so I could feel the how this 45 shoots. I LOVE IT! The muzzle reaction is milder than any 45 I've ever shot.
I do carry the 45 and will probably carry it as much or more than my full size 40 or my compact 9. I am really thinking this will be my choice. I just need some more magazines for it and they aren't easy to find from reputable sources without paying $40+. I have a friend who reloads so I can more than likely buy the components and have him show me how to reload and in the future get my own simple reloading press. May need guidance there when the time comes from you guys. I may just rotate between the 40 and 45 depending on availability and ammo.
Just a note. I found that when the muzzle came back to rest the sights were right where I left them on the target, this is something I have never had happen on any of my other guns except, i think, my Taurus 1911. I use the same grip on each one, as size allows, but wouldn't that be an attribute of the ergos of the M&P?