That's a tough choice.
I own a Glock 22 (2nd generation) and 2 full size M&Ps (9mm and .40cal).
Comparing the G22 and the M&P40:
These are two of my favorite guns. The Glock 22 was the first pistol I owned and it was given to me by my father. It was a used piece, so the trigger on it is spectacular for a polymer pistol. The only issue I ever had with it was the muzzle rise made it difficult for me to get accurate follow-up shots. I never had a problem with the grip of the pistol. The grip angle was ok for me. I was fairly accurate with the gun.
Enter the M&P40. Milder recoil. Much, much better ergonomics. Trigger is rough at first, but smooths out nicely after a few hundred rounds. As far as shooting and accuracy goes, it is a far superior pistol to me. I am more accurate with it than any Glock I own.
However, Glock has a helluva reliability record that the M&P has not yet built.
In addition, concerning the M&P45, every one I have seen has looked rough out of the box, as if the extractors were off previously used guns. The slightly larger grip on the M&P45 didn't feel as good as the 9 and 40 versions. With that being said, I still fully intend to purchase one at some point.
Then there's also magazine capacity to take into account. The G22 holds 15+1. The M&P45
currently holds 10+1. However recent email correspondence with Smith revealed that a 14-round magazine for the M&P45 would be released in 2-months or so.
Given these two choices, I would go with the G22, unless the M&P40 becomes an option.
Regardless, he is going to get a great pistol. Even if the M&P45 experiences issues, Smith's customer service is top notch and will pay all expenses to have it repaired. Glock's CS is very similar.
Tell him to not worry about which one...just worry about which one to buy, first.
Good luck to him.