I have both and agree with what Otlecs says Warlocks are the most annoying, players don't seem to notice DOT's anywhere near as much as Hunter spam,and panic much more with 5x5x5 corruption,agony and immolate on them.
Warlocks also get SoC which you can chain pump into the middle of a group for some very,very nasty AoE.
Teleport and rocket boots are something i'm looking forward to playing with when they arrive at the required levels.
So my opinion Warlocks will only get better to play.
Hope this helps.