Or haven't even shot the Colt...
I've shot the M&P15-22 and love it but I wanted the M4 heft and look of the Colt. Good arguments for both but now that the price is about the same I'd recommend anyone in the market for a dedicated .22lr AR to look at both the S&W and Colt. The 180 degree selector swith is my biggest complaint, it was dumb of Walther to do that.