depends on spec
their healing is absolute shit in pve
i haven't done much pvp and haven't heard much from them from there, but i know they're not too great in pve whatsoever. though ww does go above mistweaver as far as i know in pve.
true dat.
i know nothing about healing though. i tried healing a lvl 30 dungeon on my monk once. i managed to keep them alive but let's just say it's not my thing.