I have two Smith & Wesson M&P 22's. Both have been nothing but a pleasure to shoot and very reliable. One has over 1,000 rounds through it and shows no wear whatsoever. The other one, my son's, has around 600 rounds thought it, again with no wear or other problems. After renting a variety of guns he chose the M&P 22 and could not happier. Regardless of where it is made, who made it or what it is made out of, the M&P 22 is an excellent gun. Every bit the equal of the Ruger SR22 in a larger sizes package. I know a few other M&P 22 owners, none of whom ever complain about them. And even of one did develop issues, S&W has one of the best warranties and customer service in the business. So no worries.
Congrats on your purchase! I have no doubt that you will love it.