The currently-latest version is working (for the time-being), but with the removal of the required API function, it's just a matter of time until it breaks again, and with YouTube's insistence of removing this, it will probably be a never-ending uphill-battle to keep it working (until it's just not possible).

The FAQ says the add-on is resorting to estimates and guesses to approximate the dislike counter, so it's not going to help much, especially for new videos. Google will get its way no matter what. 😒

Also, the ratio bar isn't customizable like with some other add-ons. The grey-on-grey bar is useless, a red-green bar is MUCH better.

(It's hilarious that the devs think that statistics think that they can get any sort of useful data to approximate the data. I guess they've never heard of things like old videos suddenly getting attention or new videos going viral or whatever. 🙄 Also, they think they can extrapolate data from videos to represent all videos. 😂)