HN is pretty close to the news feed I had in Reader.
Google Reader had reshares, not upvotes. The only indication you had for "is this an article worth reading?" beyond the actual headline was the number of friends who reshared the same article. However, unlike any other social network, Google Reader wouldn't show me who reshared an article first, nor would you get any imaginary points for sharing something interesting. As such, there was no gamified hunt for "karma" or "upvotes" or whatever. There was no incentive for resharing other than "I read/watched this and think it's interesting", and the result was a much more sincere curation of topics that interested your friends.
Similarly, there were no downvotes or upvotes on the discussions.
NewsBlur copied that set-up, but out of roughly 40 close friends from college who intensely used Google Reader, only five made the switch to NewsBlur. The rest ended up scattered among chat apps and other social networks.