I've got 3-4k rounds through my AA Kit. Only problem I've had with the frame is .22 sure makes it dirtier, compared to centerfire ammo, but it is a glock.
If you don't want the conversion, I find the grip angle of the Browning Buckmark to be similar to the Glock. Well, more similar than any other .22 pistol I've tried.
I believe to M&P22 is a step in the wrong direction. First, it has a thumb safety, which will make you adjust your grip. Second, I find the M&P sits lower in the hand than the glock. I believe going back & fourth between these two platforms may be counterproductive.