As long as Reincarnation is off the shared limit with other brez it will still be a great part of the shaman kit.
There's always going to be a cost to it because of that (low mana/hp). I can understand why ele and resto would be pissed at the mana though. You get around being gibbed again by being smart about your timing and communicating with healers...seriously not that hard. And if for some reason you have to do it instantly with damage doing out and no time to communicate then pray you've got a healthstone to use