This extension has my favourite implementation of the dislike counter.

It keeps both the Like and Dislike icons visible and displays the dislike count exactly where it belongs, right next to the dislike button. That's by far the most natural-looking approach.

Unfortunately, there's one major UI issue: the entire action bar below the video is shifted much too far to the left, almost touching the channel information and Subscribe button. It makes the layout look noticeably off. There's also a tiny cosmetic issue: the spacing between the dislike icon and its counter is a little too narrow.

For comparison:
- Return YouTube Dislike replaces the dislike icon with the counter, making it impossible to tell whether you've disliked a video.
- YouTube Dislike Counter keeps the original icons but places the dislike counter far away from the rating buttons.

Fixing the action bar alignment would make this my clear favourite.

Update: I found an interesting workaround: using this extension together with Return YouTube Dislike often fixes the action bar alignment while preserving both thumb icons and the dislike counter. Sadly, this doesn't work consistently and may break after refreshing the page, so it's currently more of an accidental compatibility quirk than a proper solution.

Marche très bien, mais seulement en version bureau.