One big difference I'm noticing already with Julien is that he plays his best players in critical situations and doesn't punish mistakes by benching players, both contrary to Therrien. How many times did a young player make a mistake under Therrien only to ride the pine the rest of the game? Julien is almost the opposite - he'll put guys right back out there, and, shockingly, it's paying dividends by showing support in his players.
And look at the GWG last night. Under Therrien, absolutely no way in hell is AGally out there with Patches, Rads and Weber on the 4 on 3. Probably he'd have some awful group like Plekanec, Shaw, Patches and Weber. Instead Julien puts his best players out there, shows confidence in AGally, who ultimately wins a big faceoff and scores the winning goal. Really loving that aspect of Julien so far.