What Reeder shows on the left is the summary of the article; one can read the original by right arrowing. Many of my feeds put the full article into the summary. I navigate up and down the list (which is all of my feeds sorted by date ascending) with the j/k keys. I don't know how NNW does it. Or did it.
It sounds nice and all, but it's definitely not a River of News style reader.
RoN style is one pane, all of the stories from all feeds laid out, newest to oldest, in one pane, and you just scroll through them reading when something looks interesting. Think the way planet aggregators work.
https://homonculus.net/images/reeder.png
What Reeder shows on the left is the summary of the article; one can read the original by right arrowing. Many of my feeds put the full article into the summary. I navigate up and down the list (which is all of my feeds sorted by date ascending) with the j/k keys. I don't know how NNW does it. Or did it.