Only tried the orc and draenei totem quests, and orc was by far more annoying.
The worst part about them is travel time though, so the longer you can put them off, the faster they will be. Best would be getting powerleveled to 55ish and doing them then. Not only do you have 100% ground mount to cut down on all the errand time, the xp reward scales with your level and raf bonus, so you can easily get 3+ levels. It still won't beat powergrinding ramps in xp/hour, but its the best xp return for time you have to spend anyway.