WotLK AoE question

[Lawwl]

Which is more effective way of aoe'ing? Rain of Fire or Seed of Corruption? I mainly ask this for halion hc adds, but I guess the same applies to a regular trash clears. Does it depend on the number of adds? On a length of a fight? On a spec (demo or affliction)?

[Vaelicious]

Seed as demo and affi, rain of fire as destro just make sure to have backdraft up