Pros: The M&P comes with a decent quality LPK (the trigger is made by S&W and stamped with a small S), MP tested bolt, a nice carrier, the buffer tube kit used on it is high quality, overall the parts used are certainly middle of the road or better based on my experience, never shot with a rest, but standing/braced it was a great shooter
Cons: mine had a lot of rattle, loose fit between the upper and lower (I ended up selling it and building an aero receiver with the tension screw, amazing), the hand guard rattled, the stock rattled..all fixable issues