Bad JuJu on a Voidlock seems pretty nasty in pvp. In pve it is really, really good. Impact is pretty sucky, but the extra bursts seem to make it a different gun it's crazy. Rapid fire gives it good flexibility, and it has decent range and recoil so I'd say the clean winner is JuJu. Thorn is top tier now for sure but it still requires finesse to use properly. RNG hates me right now so I don't have a vex. Yet :P