What the guy above me said, longevity. You could use Giga Drain, but that depends on your opponent not resisting Grass. You can also get at least 1 more QD if you play your cards right, which could be the game-changer.
that makes perfect sense, actually. i still prefer giga drain, but i suppose that's just a matter of playstyle and the team i built around my rain volcarona.
i think this discussion has died down a bit. if anyone wants to move on, i'm kind of interested in thoughts on amoonguss. when regenerator was released, the mushroom got all sorts of crazy high usage, but it seems to have died down very quickly. is this due to the prevalence of tornadus-t, the advent of more offensive teams in the metagame, or simply a fluke? have people forgotten about amoonguss, or will it see a rise in usage again once (if?) this extremely offensive metagame calms down? your thoughts.