I like subcaliber practice, agreeing with Jeff Cooper who said "You can learn about 80% of what you need to know with a .22."
I have an Ace, a Kadet Conversion, and a K22 for the purpose.
I use them for warmup on the draw and target transitions. I do not double tap with a .22, the lack of recoil will give you funny ideas. I normally shoot some centerfire after warmup with the .22.
The problem with the M&P .22 is, as you have seen, that it is not an M&P. It looks and hefts like one, but the swinging hammer lockwork completely changes the actual shooting. Maybe somebody will bring out a conversion like you can get for 1911, CZ, and Glock.