I've been using Enhancer for YouTube since a couple of years ago and I can say this is one of the best and more practical extensions I have used.
It makes using YouTube much easier and doesn't interfere with your browsing.
I simply love it.

the best and has lots of features really useful

recently the miniplayer still appears despite being turned off

The ad blocking feature is wonderful. Before I used this so much time was wasted on annoying ads.

Easy to use. No fuss. Superb.

one of the best extention

This add-on is quite amazing.