I do 10-45 with an 80 frost mage 3 pull sfk, single pull armory and cath, you'd probably be better off doing the lower levels with a lower boost char for more xp though.
45-60 with an 80 blood DK in scholo clearing to before the whelps.
61-66,67 I boost in Ramparts with the DK then pretty much quest the rest of the way.

1-60 Takes 8-10hrs with RAF.