Doing the RAF Boosting thing now, and I've found that the most time-consuming thing is leveling to 10-12 until you can get the team to an instance, and then setting up a summon rotation to quickly get the team to a new instance.

I still think the most annoying instance to boost in is ZF due to the mobs that Hex. Nothing more humiliating that having my DK die in a level 45 instance :(