Yeah, I wonder if there is a cheap way to test this. Actually! There could be! Like using favorite's here on hacker news. That could be mined and visualized in various ways. (Although a quick sample shows me that it's a rarely used feature)

> I was also wondering what would be good options to store votes/upvotes in a decentralized way.

Yeah there are a lot of interesting optimization challenges if you really want to utilize upvote graphs for ranking.