Welcome to WebmasterWorld Guest from 220.127.116.11
Like you I have tried many client side apps but found them to be slow or not developed enough.
Keep an eye out for the new version of Internet Explorer, it is ment to have a built in RSS reader, thats if anyone is still using IE by then.
There will be a complete control panel for "brands" to display whatever information they want even if they dont have an rss feed.
Hopefully this post will remain.
The brand will be able to see how many users have downloaded and subscribed to their feed.