I leveled two mages into their mid 30's, and just got tired of the downtime, they were always drinking, and they died constantly. 1-30 was a breeze, 30-40 was a pain. All that plus no real tanking/kiting ability, and I just gave up, for now. I want to try them together at 60, see how they do then, with arcane explosion farming.

So I broke one off and she's been leveling with my druid, and they mow much faster through mobs and quests, and the mages portals makes questing for both of them a LOT easier. The other is still at 35, but he'll get back in the game at some point. I might pair him off with a hunter, see how that goes.