Great add-on Rated 4 out of 5 stars

Love this add-on because it somehow improved the video buffering speed. So my videos do not stall anymore. Thank you! The only problem is when I want to navigate back to a previous page on youtube from a video, I have to click the back button several times for it go back. If I click it once, it just reloads the present page. I have only experience this problem with this add-on enabled.

This review is for a previous version of the add-on (0.2). 

The history problem is finally fixed! :)
The new version has not been reviewed by Mozilla yet. If you don't want to wait, you can download the new version from this site: https://addons.mozilla.org/en-US/firefox/addon/youtube-html5-video/versions/