I havn't been raiding with a guild in a while, but I ran a BoT10 PuG a few hours ago as Discipline, and decided to try AA/A out since I usually go ToT/SoS. The group had no melee DPS, though we were also running Holy Paladin, Holy Priest, Disc priest. I think I am liking Archangel.
In my opinion, both should be fine, it will just come down to your play style, like most everything does.
edit: The group comp was: Prot Warrior, Prot Warrior, Survival Hunter, Marksman Hunter, Fire Mage, Shadow priest, Destruction Warlock, Holy Paladin, Holy Priest, Discipline Priest.