Newsblur is great in concept but I think the UX could be much better and more responsive. Frankly, the Google Reader UX is simpler and more fluid, commonly where NewsBlur adds on top of Reader UX is actually worse. The UI loading time on a desktop browser is usually more than 1000ms. It is harder to manipulate feeds on the left nav than Reader and the UI is “thicker” in pixel count.
The UX on iPhone is slow and not as good as Reader or Feedly. As a user, I rarely have the need for offline syncing since I generally am not on an airplane or a remote area during the work week, so waiting for that feature is not as compelling as it might be to frequent travelers.
Also the backend messaging system seems to repeat messages every so often and indicate the existences of queues. I would use less queues or buffers when working on a large scale system. HTTP service calls are cheap and if one monitored the number of failed HTTP calls, generally it is as good as a queue. Most of the available modern queuing systems in Python and others (JMS, SQS) are all built on HTTP service calls anyway.
In short, I paid for the services thinking this was a great thing you built, but now I would like my money back.