What other HK's do you have? I have had both and like the USP better. The M&P is a very nice gun though.The grip is smaller than the USP 45 and the USP is lighter on recoil. Boils down to what you like better and what you shoot better IMO. The USP's at CDNN are priced very nice.
I have HK45C, P30 in 9mm & 40.
Thank You all for feedback, keep it coming. Still torn, no funds for both, M&P is different, feels really good, but I rarely take anything to range but my HKs.
My HK USP 45 is my favorite pistol in my collection. Wouldn't part with it. The only gripe I have heard about it is the large dimensions. I have huge hands and it fits me perfectly.
I don't have the largest hands, but the USP 9mm (handled a used one @ LGS, never fired one, shop wouldn't allow dry fire, even w/ snap cap), didn't seem to large, not sure about 45