S&W will stand behind you and send you a UPS sticker to ship the gun back to make it right if you ever have a single issue that you feel is worth your trouble.
I am not only trusting my life to my M&P's but am confident in the manufacturer to address any problem. I once had a FTF in my M&P 45 compact because I was using crappy reload target ammo. But I called S&W about it. When I figured out the problem, I never used the shipping sticker and got two free 45c mags because of a gun show hassle where I bought the gun.
The LASD / S&W investigation continues, and maybe S&W will have a statement addressing the matter some day soon.