I am a big fan of both Glock and M&Ps. I like the grip on the M&P better but I can adapt to either one and rock them both.
I think the Glock trigger (blade safety) is a better design than the hinged S&W trigger. The successful APEX forward set sear can be had with the stock trigger, a two choices in aluminum with a blade safety, either curved or flat.
Perhaps the stock Glock barrels are better than S&W, idk. My Pro 9 seems as accurate as I need it to be. I am likely going to get the APEX grade barrel as my next upgrade.

The secondary market reflects generally higher prices for Glocks over M&Ps.

If I was going to stay stock I'd get a Glock. I can live the with the grip angle and prefer the trigger.

I bought my M&P Pro 9 and sold my G17 mostly due to the superior ergonomics of the M&P. The trigger was okay and as I improved my skills I recognized that the trigger was the place to improve my M&P. So I went for the APEX Flat faced trigger. $155 on Amazon (prime too).
If I was to start from scratch now, I'd get a M&P 9 FS (not pro) for $400 off armslist. I'd put in the APEX grade barrel and flat faced trigger. I like the 4lb trigger return spring. Feels great to me.