My biggest problem with reeder is that in order to navigate articles you need to swipe down or up. This is ok if you have short articles but if they are long you have to scroll all the way through the article to get onto the next one.

I know there are up and down buttons but these are hard to hit and break the fluidity of scrolling through feeds.

Byline navigates through feeds left to right, which if find a lot easier, the only problem with byline is it's got a bit buggy and is very pre ios7 themed.