I haven't seen Schwarz play, but I can offer an opinion on Montoya, having watched him the last 2 years at Michigan.
Basically, his style is the second coming of Marty Turco. So much in fact I have heard other fans refer to him as "Monturco". Monty doesn't really play a straight butterfly or anything else, just whatever he feels is the best way to stop the puck. He seems to be playing largely on instinct right now, I expect his technique will become more refined with time. This happened with Turco too, who was quite raw as an underclass player and flopped around too much, but learned to control himself better while still using his athleticism by the time he was a senior.
Montoya's a decent puckhandler, although not as good as Turco. He also needs some work on his rebound control, he sometimes leaves them in front when they could have been safely directed to the corner. Those are things I expect to see continued improvement on. Good things about him are his focus in "big games" and the athletic ability to make the impossible save when a sure goal is imminent. Those qualities make him a great prospect.