Sorry for the harsh review but this addon has a HUGE issue that hasn't been fixed in a year.
Every now and then, randomly, this addon will stop working. The advanced control features will go away permanently.
Literally the only way to fix it is to reset all cache & cookies. Other reviews bring this up too, it's not just my machine.

This is very infuriating. On one hand, the features of this addon are incredibly useful, and it's annoying to use Youtube without it.
On the other hand, I don't want to keep losing ALL my website logins & settings just to keep it working. I didn't want to write this review but after a year I don't think this is ever going to be fixed.