It's a must.

Powerful, easy to use, crazy amount of settings, active developers who care about their plugin, contains an ad blocker (with white list for creators you want to support), and best of all, it's free! If you watch anything on YouTube, this is a must have. You will *not* regret installing it.

Very simple to use, unobtrusive tool that does exactly what it is named for, enhancing YouTube.

It does all I want and more, very happy with it.

WOW!! This is one of my favorite! Enhancer for YouTube, You have done it!!
I have often missed these choices! And it works really well! Bugs? Yes, everything has bugs, but you are constantly working to improve and improve !! Hope YouTube and Firefox really take this addition up to 100% ..
Over and out and take care! Blessings to Your Comapany! Best Regards Karl-Bo Lundstedt "KB"

Great, does what it says it will do. While I don't suggest blocking ads for creators that you enjoy (so they get revenue) it is nice to have HD auto selected.

SELLOUT update description Clap2 OMEGALUL
I should probably "Report this add-on for abuse" HYPERLUL
Nah, just kidding. Awesome extension. Probably the best for YouTube, honoring its name. It deserves more than 4 stars to me and I completely customized mine. The only thing I'd like to see in the future for now is a wider "loop bar" since it's too short in horizontal length and consequently some seconds are impossible to select.

Great extension, does what I want it to do which is disable autoplay, plus it has some other good features like a fixed player when you scroll down a page and various themes to chose from (I recommend Arc Dark).

WOOOOOOOOO!

This thing is soooo handy! Modifies video playback (speed, video size, volume) in ways that YouTube doesn't offer by default. Also, really great for dimming the screen to reduce eye strain

This add-on is really great. Thanks so much for these extra options for Youtube. I especially like being able to prevent automatic playback when a video is opened. Thank you!

Makes youtube actually usable and far more flexible, it's pretty great.