Metamorphosis is not as good as everyone thinks it is... It's nice, seems fun but not OMG...
Obviously is something locks always wanted: a dps cooldown, but makes them easy prey to new CC and requires them to forget that sl/sl build everyone hates. Still it's in the pet tree and those 40% extra dps aren't real 40% extra dps...
And I have to say that my shaman would love your dispersion for PVP...
Can be used while in CC!! + 90% damage reduction + 6% mana every second... Wouldn't call it bad