Roughly 25% of the time the extension fails to load. Meaning if you aren't paying careful attention as the page is loading you could get BLASTED with loud audio that you would assume you could attenuate with the mouse wheel... until you try it only to realize that the extension didn't load and so you proceed to get blasted with loud audio until you turn down the volume some other way.
There will be times you would be watching something in 240/360/480p and sometimes you assume that it's just the best quality available until you finally realize that the extension didn't load and Youtube just decided to play it for you in the aforementioned terrible resolution.
Lastly I do NOT care about "What's new in Enhancer for YouTube" at all. And the fact that there is no way at all to disable the whats new thing from popping up is pretty frustrating.

Does not support the current ESR version 115, which should always be the minimum requirement for add-ons. Now I have to sit and wait for the fix untily July :(

Muy buena, anda de 10!

i used it until 2 months ago. now i can not use it unless i buy windows 10 or high computer.
i will change rating to a 5 star when i can use on win 8.1 computer

I love being able to scroll down and read comments or see what else I can listen to and not miss what I'm watching at the same time. Volume enhancer is a great addition because some videos can be too soft to hear.

ITS BACK!!!! I've been waiting for it to come back! This is a must need extension for youtube! This and UBlock! It allows much more customization and speed when on youtube! If you're thinking of getting it you better hurry! Sometimes it dissapears from the Addons Store!