Pretty good experience so far. I believe it could be improved.

You're limited to 4 simultaneous downloads, which obviously matters when you need to download a big volume of videos. 4 downloads is pretty decent deal, however it can get lower than that if one of your downloads couldn't start of properly - this will reduce your number of simultaneous downloads by one... until you reload the extension.

It is possible that sometimes downloads may crash - regardless of how good your internet connection is. In my experience, i had around 15 total failed downloads out of around 240 downloads made. It's not much, but it's worth mentioning that it can happen.

Another thing. Last time i tried - it was unable to pick up streamed content such as spotify music. I believe it would be a huge improvement to extension - making it more diverse.