So for those that have shot both, Glock or M&P? I doubt I can get my hands on a Springfield to feel one up, variety is a bit limited here in the 'Peg. Never mind the Steyr.
Accessories won't be that important to me, looking for something shootable out of the box. To me that's more of a test of a decent product.
I own a g19 and a m&p9.
They're very similar in the fact that they're both boringly reliable. Mine just work, always.
Accuracy wise, same deal. They're both as accurate as the shooter holding them, and they'll both shoot low-left for someone who snatches at the trigger. Both can hit a 2" target at 20m in my hands, and surely much tighter in better hands.
I prefer glock triggers for their amount of feel both at the wall, and at the reset.
I prefer working on glocks, and I prefer the grip angle as it puts a bit more force on locking bones into position.
The m&p has a nicer feel in the shape of the grip, but when you squeeze the way you're suppose to, the glock has the edge on friction, which equals recoil management.
I've never shot an xd, but don't plan to either. I've read varying reviews on their quality, but my real issue lies in their copying glocks safe-action trigger(which promotes responsible gun handling), and then they go add a useless secondary safety to the grip.
Pistols have holsters to protect their triggers while loaded and not in use, and I have a brain attached to my trigger finger.