Amazing. A-ma-ZING!
It works flawlessly, is very easy to configure, and it does wonders. Dynamic previews was the reason I first installed it, but I'm staying for all the other improvements, disabling annotations and subtitles, mini vid while we scroll to read comments, persistence of the mini vid even when we click elsewhere in youtube, popupped mode, one-click ban of pestilent channels...
This extension does wonders, I am extremely grateful, thank you.