Thanks for the input -- any thought as to how much faster boosting would be compared to 5 man leveling (using quests & instance mix)?

My options for boosting is 4 sham+

either a decently geared prot pally

or a poorly geared frost mage (both 70 of course).

I am a bit worried that at 31 I have passed the levels where boosting really out shines 'normal' leveling.