When comparing Vienna vs Reeder, the Slant community recommends Reeder for most people. In the question“What are the best RSS readers for Mac OS X?” Reeder is ranked 2nd while Vienna is ranked 4th. The most important reason people chose Reeder is:
Integrates with Instapaper, Pocket and Readability.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Open Source
Vienna is an Open Source project. That means that every single detail of its implementation is freely available.
Pro Great Interface
Pro Powerful keyboard navigation
There are easy to remember single keystrokes to scroll through a post, mark it a (un-) read etc.
Pro Integrates with read-it later apps
Integrates with Instapaper, Pocket and Readability.
Pro Integrates with a wide variety of RSS services
Reeder supports Feedbin, Feedly, Feed Wrangler, Fever, FeedHQ, Inoreader, NewsBlur, Minimal Reader, The Old Reader and BazQux Reader.
Pro Has dark theme
Beautiful dark theme for best reading.
Pro Integrates with Instapaper
Pro Nice keyboard shortcuts
You can also customise keyboard shortcuts.
Cons
Con No longer functions as Apple blocks its launch for security reasons
This have been fixed.
Con Can't remove unused tags
Once you create a tag, it will always show up in tag selection screen. There's no way to delete it from the list.
Con Can't edit tags
If you've made a typo, you have to create a new tag. You can't rename the existing one.