Is there another skill that works with Slaking or is it “balanced” the way it is?

Insane stats, nerfed by a useless ability. I've never used one precisely because of this, so I wanted to know if you think it's fine as is, or if another ability would work with it, like Regigigas's "slow start." I don't follow competitive play much, but the few times I've seen it, it hasn't appeared anywhere, which makes sense.