Originally Posted by
Imnick
Frost Bomb is undeniably better than Living Bomb on Ta'Yak heroic and debateably better on Normal, because it has a much higher DPS output.
Some people just don't like using it because it has a cast time and feels weird.
Frost and Arcane Mages that only have Light of the Cosmos and Relic of Yu'Lon however will not be able to use Frost Bomb because it will not proc Light of the Cosmos, so will use Living Bomb until they get an Essence of Terror.
Using Nether Tempest on Ta'Yak is just insanity.
You will spend so much time refreshing it that you will not be able to perform any other DPS spell, and without putting it on all targets it only ticks on two. The Fire Blast glyph does not add enough damage to make it worth using over the other two because you would not want to Fire Blast on cooldown anyway.
On single target such as Blade Lord, Frost Bomb is theoretically the highest damage but in practice loses out to the other two because it is harder to have 100% uptime. Living Bomb and Nether Tempest are roughly equal and it just depends which you think looks prettier and is easier to refresh. Living Bomb has a 3 second grace period, but if you recast it before then it won't explode and you lose 50% of the damage. Nether Tempest has a 1-2 seconds grace period but you lose only a couple of ticks refreshing it early.
No Mage Bomb can proc Hot Streak. It will only proc Arcane Missiles on Application. How it procs Brain Freeze varies by bomb but they are of roughly equal worth and do not increase in value with multiple targets.