This is an excellent, must-have extension, IMO.
I highly recommend getting the full version to get full 1080p downloads, the asking price is more than reasonable, a pittance, really. The extension delivers and the developer keeps on top of it to stay one step ahead of google.

Update for March of 2024, Google/YouTube has broken the extension with more code changes and their recent tear on extorting every penny they can get, but the developer is working on it.
If you've just downloaded the extension for the first time ever,and are disappointed, just sit tight, this is hands down the best YT downloader out there.
If only more people would use Rumble though... *sigh*