After using many other video download add-ons, I think I enjoy this one's the best for it's sheer simplicity. A couple of minor tweaks would make this an app I would gladly pay for:

1) sometimes the downloads get "stuck". There is an option to reload the extension, which does fix the problem. It also deletes the existing download. Would be nice to have the existing download just "pick up", similar to how Firefox automatically restores your crashed pages.

2) the user interface can seem complicated for a non-geek, I would imagine. Perhaps simplify it a bit (maybe allow people to choose "advanced options" if they want, but keep the basics...basic.

3) a "sort-by" option would be a God-send. When downloading 50 files at a time, I would love to be able to sort by percentage completed, or total file size, or whatever. This is my most-desired request.

I probably can come up with about a dozen other useful tweaks I think that would make this the most amazing downloader ever, if you want to hear them.

All in all, I'd rate this a 4 out of 5, based on the issues above. If those were fixed and/or added, I would give this 5 stars ALL day long - good job on a great free add-on!