Took me under 2days /played for both the teams I have at 60 (5xHunters and 5xMages) Currently working on Pallys(lvl 38 ATM) but I have done a lot of instances with them so not sure what it will turn out like.
I found the first 30 levels took forever and the second 30 go by really fast, Im not sure why.
Im Horde side and have a pretty good zone rotation going for post 30, but before that I dont have anything particularly great to offer.
However you must do hinterlands as horde, that place is worth 4-5 levels in about 2-3 hours, it is by far the best box friendly zone (Horde side, I have no idea about Ally) there is 1 collection quest (Tainted blood)
and its easy even with 5 toons, I never had to go back and find more blood.