Pretty good Rated 4 out of 5 stars

Pretty good implementation. One thing I would really like to see is the ability to hide the toolbars (main toolbar + feed toolbar) on a permanent basis, e.g., via options, rather than having to hide them every time I open up NewsFox. Another option I'd like to see is the ability to place separators between feeds in the feedlist. That would work better for me, and take up less real estate, than using groups. It would also be nice to be able to mark individual entries in a feed as unread, for those times when you want to return to reading them later.

In response to developer's comment below:
Geeky workarounds, especially those listed as "unsupported" on the developer's web page, are not satisfactory solutions.

This review is for a previous version of the add-on (1.0.8). 

See http://newsfox.mozdev.org/drupal/content/aboutconfig-options. Use newsfox.z.noFeedToolbar = true and newsfox.z.noMainToolbar = true in about:config. You can always use a feed with no title for a separator.