I'm hoping to find a deal on an AR style .22 this weekend from one of the shows. There are three I've seen that I like: the Sig 522, S&W M&P 15-22, and Colt M4. After doing some online research it seems the S&W M&P 15-22 and Colt have a lot of issues. Does anyone have any experience or advice with any of these models or anything similar?