I have never shot any of the M&P line of handguns. But from what I here the trigger sucks. I have held them and the ergonomics spot on.
I swear by the XD line. They are some amazing guns out the box. The only thing I have felt the need to do to my XD is shoot it. I can't say the same for my other guns that are in need of some upgrades.
Another vote for the M&P. The M&P line is very well made and utterly reliable. S&W reported that they are producing over 300 M&P's per day right now and cannot keep up with the demand, so I must not be alone in liking them. My M&P9C is a top tier gun for sure and a joy to shoot.
Personally I don't care for the high bore access of the XD and am not a fan of the grip safety. But the XD does have a solid fan base so I am sure they are good reliable guns.