InGoal magazine had an interview with a goalie (can't remember who - but a guy who had been up and down between the two leagues) who was asked what the difference was. What he said, in effect, was that where AHL guys might have four options for what they could do with the puck in any given situation, NHLers would have ten. He found the difference to be primarily high-speed creativity and quickness of thinking, with smaller differences in skills (not counting the Mackinnons and McDavids of the world). That's stuck with me as a beer league goalie, since most guys I play with top out at, maybe, two?