Try to shoot both if you can. I prefer the M&P mainly due to the ergonomics and grip angle. With an Apex kit, the M&P is really sweet. That said, Glock's rep is well earned. I really like the G19 in particular.
edit: also check out the m&p pro 9 (comes with night sights and an upgraded sear)
Either will suit you well; in fact you'll probably have your grandchildren shooting either of those 2. Of the polymer guns out there, for the price you cannot beat either Glock or the M&P line. If I weren't already so vested in Glock I would probably own an M&P and that will probably change the first time my shop gets an M&P 45 in stock!
I had several Glks but always had to get the grip reduced, I have a small hand. With the MP you have 3 different size backstraps. You can do this
with both, buy a 40cal and get a 40/9 conv bbl. I like the MP much better.
I was carrying (on different days) a GLOCK 17, and a HK P30L, I just switched to the M&P9 only. I like the way it feels in my hands and also the way it performs. Its reliability is great and so I now stake my life on the M&P9 as my primary. Its not an expensive pistol, so I feel fine beating the crap out of it a lot better than my HK. Glocks never have felt nice in my hands but their reliability is great, so thats why I carried one. The M&P9 has the same great reliability I believe.
For sure, as most have mentioned you need to fire both guns to see which you like (and which likes you) the best. For me, it is the M&P hands down. 100% flawless operation in mine.
Yes, shoot both. Flip a coin because when the coin is in the air you'll truly realize in your heart what you want the result to be. That's what I did and I now own a M&P
I've owned both a Gen 4 G17 and a M&P pro9. Both are great guns no doubt. It is mostly personal preference as I would feel competent with either. I do shoot the Glock better though. The only reason I can think of is the trigger reset on the Glock is so much more defined, you can hear it and there is no doubt the trigger has reset. M&P I have missed the reset several times. If I had never fired a Glock as much as I did I may have never noticed.
Nothing wrong with either just get the one you like the best.
I had a G19, shot a G17 several times and ultimately ended up with an M&P. I really like the ergonomics and the way the grip feels vs a Glock. I'm with the rest of the folks that you should shoot both and then make a personal decision but I think you'll find the M&P to be a damn good weapon - add the Apex upgrade parts and it makes a great gun even better. Good Luck in your decision.
Just buy both, there won't ever be a "what if..." moment when you're shooting whichever one. Probably able to even get most of your money back if you turn out to hate both and get any thing else as they are both quite popular
If you decide to go with a Glock, I'd just say go with the 19 instead. It's a much more versatile variant in my opinion. I have a Gen 4 19 that forced my Sig 229 into my gun locker. Either way though, you'll have a great gun.
Both guns are pretty good, but I'd go with a Glock. A Glock 17 if I wanted full sized, Glock 19 for intermediate size and a 26 if I wanted a more concealable compact one. Of course those are just my choices of 9mm models. Make the appropriate number changes if you want .40 or .45 (minus the intermediate sized one).