I've got an XD 9mm Service model and it's been great! Never had any problems with any variety of ammo I've fed it, although 90% of maybe 1500-200 rounds has been WWB and Rem UMC. I don't any any experience with the M&Ps. At least initially there were some reports of M&Ps dropping magazines while shooting. I don't know if that has been resolved or not, but you might check it out; however, you may find most of that is based on internet postings and weigh that accordingly. One of the original knocks on the XD had to do with the finish, but they changed the finish a year or two ago and it's reportedly up their with the famous Glock finish now.

I don't think you'll regret an XD.

P.S. If you want more detailed info on the XD, go to XDtalk.com. Great community over there and they won't flame you for considering the M&P.