I've never killed a moose with my bow (as you know moose permits in Maine are like unicorns...very hard to get) but have been in a number of close up, some VERY close up, encounters during deer season. For me one thing stood out from those experiences...a rutting bull moose at 10-20 yards is definately NOT like a deer.
These are huge animals, with a rugged bone structure, thick skin and 'get-the- $#@ out-of-my-way' attitude during the rut. With their grunting and brush-busting antics they'll make you check your pants twice when coming in close, especially in heavy brush.
If I'm ever lucky enough to hunt them I'd use the heaviest bow (at LEAST 50#), heaviest arrow and strongest two-blade broadhead I had access to and could shoot well with under pressure. Again, BIG animals here.
By the way, you probably know already but 45# is the minimum draw weight for moose in Maine.
Good luck...and don't forget to pack those extra panties, lol!