I do own and like Glocks, but how much simpler is a Glock than an M&P?
The M&P is a bit more of a pain to detail strip. Roll pins are more difficult to get out than the Glock retainer pins. More parts in the M&P with the sear, tiny sear spring, etc. The M&P slide is a bit weird in that the rear sight has to be removed(or slid over at least) in order to remove the striker safety plunger(Apex DCAEK kit has a replacement).
The M&P is what I would call difficult. It's just a good bit more tedious than the Glock - which I can fully detail strip and reassemble inside of 5 minutes. That's not really a big deal under normal, every day use, but maybe it's psychological in that I know I can replace any part in a Glock in a couple of minutes no matter where I am (assuming I have my parts kit, which I usually do).
Obviously I'm not bashing the M&P here. I love it. The ergos are so damn good... and reliability has been on par with my Glock's from my experiences. I even took my old M&P out to the desert for some shooting and did some pseudo 'torture' tests.. just dumping hand fulls of gritty desert sand all over it... and it ran just fine. I expect the same from this one.
Hopefully I can get out today or tomorrow and do some shooting with it.