Lovin' the .45!
I've owned my M&P .45 full size for just under a year now, and have 'softened' it by throwing over 1,200 rounds through it at my local outdoor range. I've used almost every brand of .45 acp ammo available with it with absolutely NO problems whatsoever, with the single exception of steel-cased TulAmmo rounds (Russian made) - in that case, I had only 2 non-fires, but they DID fire perfectly when recovered and replaced in a magazine.
I found my M&P to target low and to the left at first, but when I switched to the small backstrap, my 2-hand grip became more comfortable, and I began hitting the target centers every time. (I have big hands - the small backstrap allowed a more solid layover of my fingers, and seemed more solid - but you know - whatever works for you.)
Coolest part about a full-size auto like this is the awe you'll get from other shooters at the range that are plinking 380's and 9's. When they hear(feel) the boom from a .45, you just get this s__t-eating grin on your face.
Recoil on the M&P .45 isn't NEARLY what I thought it'd be... quite controllable, and somewhat similar to a .40, although all I've ever used are 230 grain FMJ and JHP. Good enough for me.
I am a large enough guy that I can actually USE this pistol for concealed carry, but am considering a 45c.
All in all, I LOVE my M&P .45!