I've run a pally,disc priest, 3x arcane mage for a long time ... recently subbed out 2 mages for a shaman and druid specifically for all the buffs, but am considering putting the 2 mages back for my heroic runs. My mage can double the DPS of all my other same-geared toons in heroics when spamming arcane blast ... crazy amounts of short-term DPS - easily long enough for heroics. If you just want to burn through heroics and aren't worried about gearing other toons, arcane mages will easily out-dps any other class by a good margin with AB spam. The issue with ground-target AOE was the primary reason I switched to ISboxer, and now I use it all the time ... If you want to raid or PVP, that's another story ....