Rated 4 out of 5 stars
This is the best feed reader I've tried so far.
I just have one suggestion: I have a lot of feeds I keep track of, and they tend to fall into certain categories (hobbies, school, entertainment, for example). I wanted to make separate groups for each category and move the feeds into the appropriate groups, but NewsFox only adds a copy of the feed into the new group. It doesn't move it out of the default FEEDS group, and I can't delete it from the FEEDS group. That means that I end up with duplicate copies of RSS feeds.
If it weren't for that, I'd give this plugin 5/5.
Don't look at your smart bookmarks!
There is only one copy of the feed, just as there is only one copy of a bookmark in Firefox 3, even though it may appear in many smart bookmarks. There are no folders in NewsFox, only groups that provide methods to handle the single copy of all your feeds.