warlocks do better dmg and dps than mages.
warlocks have the best curses and corruptions in all caster classes
What does mages have? Water elemental(not), warlock and banish it and put curse of touges and mages are well as dead.
Fear (Howl of terror, Death Coil, Fear)
Dot
Dot
Shadow bolt(usually 10-16k damage if they spect it like)
Shadow burn
Dead.
Don't forget to mention the felhunter to get rid of buffs
rogues and locks usually battle for top spot.
In conclusion, Mages suck.