Superlinear is terrible given the state of Steem currently. Vote trading services command a significant portion of SP, and they will start dominating exponentially were we to go back to it. Minnows will be left out more than ever.
That was along the lines of what I was suggesting, people can vote for their favourite curators, and that gives curators greater influence. It is kind of a subjective reputation system. Prone to abuse, but much less so democratized. As for the current Rep system on Steem, that's utterly meaningless.