BA is great and as a longtime EQ raider, I would love to see more 48/56 man raids.

The problem with BA is locking it in a piece of content with a 144 person cap that you cant pre-form alliances with, where everyone else in the zone probably has a desire to do it, and if they dont, BA being open actually hurts the rest of the zone significantly (48 level 60s is a gigantic amount of level 60s).