I use this extension all the time. I tried an online service a while ago, but downloading always took too long. It is very good to be able to download in different formats and different qualities. The only problem, and the one star missing is that your server should not be doing any conversion. I can't download 1080p without PRO, which makes sense because it isn't available as an mp4. However, I would like a way to download however youtube actually stores that data and ffmpeg it into an mp4 on my computer.