Get it, they are reliable and fun. They just came out with a compact version, it holds 10 rounds standard, other wise you'd be stuck trying to find 10 round mags for a regular full size model which holds 12.
Don't have the M&P .22 but have the full size 9mm and love it. As far as Ruger goes, if you are talking about the SR22 you won't be disappointed. I have one and find it a blast to shoot as it eats everything I have fed it so far. The only negative, and it's a slight negative, is the safety operates in the reverse ie: rather than sweeping it down to fire you have to push safety upward. Only time it would be an issue IMO is if you were using as a CCW. Otherwise at the range it's a terrific plinker - accurate and reliable. Easy to disassemble and clean.
We have a M&P 22 and use it for Steel Challenge, awesome pistol, very reliable and great gun to get use to the feel and function of the bigger caliber M&P series. Our's no hiccups, greater than 2k rounds through it. My best selling .22
Walther P22, had one, no longer have it for a reason and won't be looking for one in the future
Ruger SR22, very reliable, nice gun.
Sig Mosquito, ammo picky, not a fan, go with a Sig 226 in .22 or a conversion kit for a larger caliber Sig
I love my M&P 22, you can't go wrong.
One improvement you may want to do is a better sights.
My wife has a SR-22, it's also a great shooter and the stock sights are better.
The one big negative with either is that you will go through .22lr like **** through a goose!!