Different calibers, different feel, different triggers, ect. I own 2 Glock 23's and love em' both. With that said, Glock and M&P's are both excellent choices. The only way your friend could go wrong is if he didn't try both before he made his decision.
I have ZERO experience, and today rented a glock and M&P. For some reason, I seem to be relatively accurate shot, my wife is considered good for a beginner. I know nothing about the rented guns, how many rnds, care, or maintenance. The glock was all over the place, and I held the M&P to about 6" at 25', wife was about 10".