I can RAF a new set of toons to 60 in about 7-9 hours on average including travel time.
Usually 1-10 takes anywhere from one to two hours. I think that's where I can make the most progress.

1-10 Questing
10-20 SFK
20-35 SM
35-45 ZF
45-55 LBRS
55-60 Ramparts

With my DK I can just breeze through all of this stuff. I prefer LBRS to Strath because of the mob density and the route I take has me killing mobs the entire way from zone in to reset.