The most Firefox like replacement for RSS feeds that I have found. Only two dings, and both are rather minor:
(1) Converting using an export was a pain, as the previous bookmark folder structure was lost on the import and it took an hour-plus to move around my 80+ feeds and get them back to where they were originally..
(2) I wish there was a way to disable the icon and only have the article title displayed -- it is a waste of screen real estate (this is my biggest gripe!).
Otherwise, as I said, the best replacement for letting it continue to appear as if FF is managing your feeds.
Also, it works well with latest release of Cliqz.