From playing both BRD and MCH my feelings is that MCH was built around GB while BRD had WM tacked on without proper re-balancing. With GB active you have 3 instant cast (4 with Feint) and 2 procs. Add on Reload/Quick Reload with Rapid Fire and you are a walking turret yourself.

AOE depends on pack sizes and CDs. I approach packs of 4+ with bishop on hypercharge with grenado shot until out of tp, then followed with an invigorate and single shot rotation. Packs of 3 or less then use rook with lead shot kept on all enemies while single shooting. Many MCH likes using spread shot over Grenado Shot, but the positions can be tricky, esp with a random tank. You'll also find players who think that if they don't hear the pew pew of spread shot then you're not aoeing.

As for which is better, it all boils down to the player. Raw numbers can say what happens in a perfect world, but players aren't perfect. I've leveled all ranged classes to 60 and I can pull higher damage consecutively from a MCH than any other.