Downsides:

Horrible Mana Efficiency except for Mindflay
Mindflay is only 24 yard range and channeled
I use a Pally as my 5th - so I can do instances.


I did alot of PvP on the PTR with my group and the thing that was pissing me off the most was running out of mana after 2 or 3 battles. Guess I was playing a Warlock with unlimited mana for far too long. :P

-Slats