It's good, but it lags the browser a lot. Especially if you're the kind of person to keep a lot of tabs open...

Dark Reader is great and convenient, but some web-pages' color scheme are somehow in conflict of this APP's. There are contents on pages that are hidden and would only reveal itself when the Dark Reader is turned off!
Set to a lighter background would help, sometimes.
May be more preset (color) schemes from Dark Reader would help to alleviate?

Хорошо адаптируется под чёрный цвет, что мне как раз и нужно в темноте.

4.9.34 is the last version that works on my Firefox 56, so I'm keeping that one until a fix.

It was working perfectly but since the last couple of updates it flickers when loading a new page or searching.

Most of the time it works just fine. Some website's style are broken, but I'm okay with that. After the recent update, the dark mode becomes less dark. Maybe you guys are trying something. Keep up the good work!

Alt+shift+A doesn't work anymore. Please fix this issue

20Aug21. As of Big Sur 11.5.2 update, Dark Reader's functionality is broken. I've removed Dark Reader and reinstalled it. No Joy.

Works perfectly so far in Firefox Nightly on Android.
*edit* Doesn't work on THIS site, even when enabled in settings and reload. (-1 star)

Still has its issues with certain sites, but works quite well overall.

Workes very good, can recommend it to anyone.
However, I'm not using it anymore at the moment, because I somehow wasn't able to use any browser theme with it. Maybe I'm just too incompetent to find the right setting, but I if you want to use your usual Firefox theme I'd tell you not to use this.
But, as I said, I'm very impressed by the quality of the CSS filtering, and if you just care about that you should definitely give it a go.