This addon has basically been abandoned by the dev on firefox due to some vague reasons that have not been expanded upon and this my new rating and new recommendation. Look into Tweaks for Youtube from InzkDev.

Works about 10% of the time. Very rarely shows any of the controls it's supposed to

La extensión es excelente, pero deja de funcionar cada vez que quiere. En los últimos problemas que he encontrado, los controles simplemente desaparecen, volviéndola totalmente inútil.

author is simply a google droid now .
no longer works in w7 as it needs to send all your browsing data to google now plus obviously doesnt block adds etc.
shame.

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.

swear to god you used to be able to download with this thing but they probably got sued or something and now its useless for me

Не грузит видео в качестве 1080p и более, при отключении расширения всё становится в порядок

I've used this addon for like 7 years now and it's starting to feel like bloat, it makes your youtube slow. It took me a while to figure out why my youtube acted so weird and solved it by disabling this plugin. Until it's updated to be faster, i cannot recommend it anymore.

шортсы не скрывает, перемотка стала 0.25 реруглироваться, хотя раньше можно было регулировать по 0.1 до 5 кратной скорости

loop control has vanished

Control panel appears sporadically but for most of the time, it doesn't work.

Hay un detalle, cuando pego un link y entra a YouTube o cuando abro el video en una nueva pestaña, no esta las opciones de Enhancer for YouTube™, como si se desactivara el addon. No me gusto ese bug, tuve que desactivarlo.

There is a detail, when I paste a link and enter YouTube or when I open the video in a new tab, there is no Enhancer for YouTube™ options, as if the addon is disabled. I did not like that bug, I had to disable it

AWFUL, never fucking works. Wasted all my time in the settings, only for the buttons to only show up sometimes. Id give this 0 stars if I could, its useless since it never wants to actually work.

이거때문에 특정구간에 자꾸 멈추는거 같음. 꼭 광고보는것처럼 한참 버퍼링생김. 이거 끄니까 잘되네.

Хорошее дополнение, но работает с вероятностью в несколько процентов. На некоторых видео приходится перезагружать страницу несколько десятков раз, чтобы этот энхансер включился.

When it decides to work, it's awesome. However, I've had this extension installed for a couple weeks and it justdoesn't work on most videos. Haven't found a reason for that yet, it just randomly breaks out of nowhere.

Updates slower than Microsoft Edge