Tried this while waiting for Reeder to get updated to work with Feedly et. al.; I still think Reeder has the edge in usability and presentation, but there's no denying ReadKit has more functionality, synching with every RSS sync engine I know of.
When Reeder *finally* gets updated, I'll probably switch back to it, if only because I use the iPhone and iPad versions, but that takes nothing away from ReadKit, it's one of the best readers anywhere.