As much as I would use NNW right away but it isn't really a useful service at this point in time.
[1]: https://github.com/Ranchero-Software/NetNewsWire/issues/491
I'm not a big innoreader fan but their mobile app is decent and their online service is synced together. In this case, I never have to worry about my "read" states getting out of sync.
When it comes to RSS adoption, the read-state needs to be seamless across all platforms.
BTW, NNW is not charging as of yet. What I was talking about in two of my messages above, is the adoption issue with disparate platforms without the availability of read-state feature. If I use NNW mobile, I'm bound to using it all the time (which is not practical). If I use it's desktop app, I'm bound to using it on my Mac all the time (again, not practical). Anyone with more than hundred or more feeds, would find issues adopting such service. I am not here to defend my likeness of NNW so I won't say anything in this regard.