Same here. Just gave quick tour for both of them and don't like them at all. TheOldReader UI with crazy spacing between elements drives me crazy. Feedly on other hand wastes too much space. Will not use none of them as replacement.
Devoted feedly user here. If you switch to 'Title only-view' and switch the display density to 'condensed' in the settings (Click user profile pic --> Settings --> Appearance), I think that should solve your annoyances. I too hate needless spacing between elements.
I was able to get Inoreader to visually look very similar to Digg reader. I do not want to use Feedly yet because the free version seems to too restricted. I'll try using Inoreader for few days before I make a decision.