Seems to be significant downgrade in the video's quality while viewing it on the forum vs opening the video in a new tab. Obviously the top image is larger and therefore will look worse, but this seems like the difference between HD and SD.
You can if you use the Developer version. However things are more prone to breaking randomly (though it's not too bad, just the odd bug once every so often). I switched to it a while ago as I needed some unmaintained addons to function.