This WAS a very good extension.
Hopefully it will be again--soon.
Currently the thousands of videos that I have downloaded over the years are mostly unavailable. If any future upgrade of this extension doesn't make those old files available again I feel I may as well start from scratch with another extension. I hope it doesn't come to that, though.
The mechanics of one downloader or another aren't really all that important to me--the real value is in those old videos. If they are "gone" I probably will be too.