Okay ... There's obviously some confusion, judging by how Ausar edited the Doom Cloud page. Chaos Toss is the primary that lobs orbs of poison, while the Doom Cloud is the one that lets out a rain of bullets.
Doom Cloud is somewhat overpowered, yes.
Chaos Toss is sort of underpowered for something that is supposedly meant to be like an offensive Mother of Nature, and is in need of a slight buff.