Problem is the M&P 22 isn't dealer transferable in MA, so not many of us from this state can provide any input on it. I've been holding out for one, but I'm about to give up hope of getting one.
Just per my internet research though, I have heard nothing but good things about either pistol.
I swear I fondled one at 4Seasons but went with the SR22 instead. Guy told me it was less picky with ammo. Not sure how true this is as I've never shot the MP22