I know it's been brought up before, but the more people who bring this up, the better. Praetorium usually takes about an hour, while Castrum takes about 45 minutes. However, Praetorium currently gives over twice the amount of experience. And as a consequence, Castrum takes longer, because of people leaving to try and get Praetorium. I spent nearly twenty minutes sitting with three other DPSs and a healer, waiting for something. We finally just started the dungeon with just the five of us, and managed to get past the first boss before we got tank/healers that would stick around.

The Solution:
Up to Experience drop for Castrum to make it more in line with Praetorium. On current, I'm only getting half a level, roughly, for Castrum runs, while Praetorium gives me a level and a half, typically. This is the ideal solution, and would be an easy implemented fix.