If you have any kind of booster, and you're looking to hit the high levels fast, I'd recommend creating two new accounts, one recruits the other, and the use anything, and 80,85,90, etc. to boost. It's still considerably faster than just about anything out there.

With the new RAF, if you have some gold around, you can hire a raid geared... anything, especially warlock or blood dk, to boost you 80-85 in... wait for it... 25 minutes. maybe like 11 minutes if you happen to have a couple 300% xp pots. There are also, and I won't give them away, some 85-90 boosting spots you can hire a geared player to help you with. Cut that awful grind from 20-40 hours to only a few hours max.