Been about equal for me as far as instances/quests. I averaged about 200k/hr taking my time doing quests from 70-72. Running UK I get about 220k/hr unrested at 72 (not looting). For content/money/rep the quests are better...for mindless leveling - instances are better (I watch tv while I run them). All depends what kind of mood you are in I suppose.

and yes...thank you Blizzard for making almost all of the gear from quests either ret pally or enhancement shaman. I replaced my paladin's shoulders and sold or de'd everything else. Let us know what the xp/hr is for BC heroics...I've wondered but just not bothered wandering back there.