The Smith & Wesson M&P 15-22 is a great rifle. Glad to hear you're enjoying yours. It'll serve you well for a long time.
I've got it along with it's big brother. Both are decked out identically (Wilson Combat triggers, Leupold XV-R Patrol scopes, etc., etc.) for interchangeability and consistency. I've probably put well over 10k rounds through the M&P 15-22, maybe even closer to 15k given my wife uses it as well, and still running just as strong as the day I bought it without any issues.