For my 2 cents when it comes to outdoor questing, nothing beats a warlock/hunter. Set up your macros so that your main is one of the lobies and tag mobs then have a macro to send in your warlock/hunter pet. You not only get full exp for the kill but the real benefit is that it is super relaxing. I never tried a hunter so I only speak from lock experience, but I assume hunter pets pretty much do the same thing.

Its like having your own AI controlled level 70 minion to do your dirty work. The felguard pretty much 1-3 shots anything up through about level 50, they still own after that they just don't wtfpwn in seconds.

I'm sure boosting is faster but for my money questing is way less burnout. With raf the the ability to get full exp from tagging first really adds up too.

Edit* if it was not clear the warlock/huner is not grouped with your lobies and they cannot do any other damage to get the full exp for the kill, just send in pet.