So on the accuracy front...
Some have misinterpreted my choice to put an Apex barrel in my guns to mean that you have to put an aftermarket barrel in the guns to make them shoot. That's not necessarily so. Every 2.0 I've shot will hold black at 25 yards easily with decent ammunition, and probably significantly better than that if you have the time to actually run the gun properly to test it. Usually I'm shooting a gun that isn't mine to briefly troubleshoot for a client so the time and opportunity to really see what it's capable of isn't there.
A retired LE buddy of mine swapped to an M&P compact recently and when we were out at the range I checked his zero on my target where I'd already checked and tweaked the zero on my compact:
Those three rounds in the 6:00 of the 10 ring were the three I fired from his gun to validate zero. This was with Blazer aluminum 115 grain. Three rounds holding hands at 25 yards fired offhand with a stock barrel.
Afterwards we did a little more 25 yard shooting where he was easily holding black and he said "I've never shot anything like this at 25 in my life."
He'd been asking about whether or not he needed an Apex barrel in his gun. I'd say no.
My Apex barrels are really, really nice. They let me hold the X ring at 25 yards when I do my part on the trigger. If you're looking for maximum accuracy out of the M&P platform you most definitely want one. But don't think you need one to make an M&P shoot accurately. If you identify that the gun you end up with does need a barrel to improve accuracy, by all means go for it. Highly recommended.
But don't assume that it's a requirement.