Rated 4 out of 5 stars

from YouTube:
"To get an RSS feed of a single channel’s uploads, paste the channel URL into your RSS reader."
this does not work in NewsFox, however the browser does not always discover the feed either so this may not be a NF issue

as others have requested, a search function is needed - the "keyword" option is very limited and not a suitable alternative

as other have noticed, only one change at a time can be made to some of the options (noticed when setting sort options), after which you have to re-open the options UI to make another change - setting more than one change results in all but the first one (or last, i forget) being lost

the context menu option to hide the feed toolbar is not remembered across sessions - also seems reasonable to combine the feed and main toolbars perhaps to save space???

if you delete a feed from a folder other than the default 'feed' folder, the feed may not be deleted from the global feeds, even if it is not used in any other folder/category - since there is an option to set the cats/folders that a feed appears in, as well as a delete prompt, it should be deleted globally when deleting it ... after all, "delete" means "delete", not remove from the selected cat/folder

This review is for a previous version of the add-on (1.0.9.2.1-signed).  This user has other reviews of this add-on.

>as other have noticed, only one change at a time can be made to some of the options (noticed when setting sort options), after which you have to re-open the options UI to make another change - setting more than one change results in all but the first one (or last, i forget) being lost

-help wanted
-https://www.mozdev.org/bugs/show_bug.cgi?id=25759

>the context menu option to hide the feed toolbar is not remembered across sessions - also seems reasonable to combine the feed and main toolbars perhaps to save space???

-https://www.mozdev.org/bugs/show_bug.cgi?id=20986 (this answer from 2009 is in your previous review)
-you can do it in CSS: http://newsfox.mozdev.org/rss/2008.html#nf27

>if you delete a feed from a folder other than the default 'feed' folder, the feed may not be deleted from the global feeds

-I don't think this is true