So the more I mess around on the beta, the more I think it might be more fun to put the Alliance army on hold until after 5.0 drops. It seems like leveling, particularly for a class like warlock, could be a lot more enjoyable once the changes to basic talents and mechanics are in place for MoP. So I may switch my one toon at a time approach for now and just focus on getting the hunter through those last nine levels.
At this point, the alliance army has managed to gain at total of 38 levels so far at this point in July, so things are moving along really nicely. Switching from dungeon finder to questing has made a big difference as well as I seem to be able to get three levels out of a full set of rested xp instead of just the two that I was getting from dungeon finder - the difference being the xp from the quest turn ins.
I'm still not sure that the quested approach is actually faster, although it seems to still be moving at a decent pace for the levels gains. Unfortunately, xp per hour tends to fluctuate way too much at lower levels to be able to get a decent read on what the true differences are.