does it's job perfectly. firefox must include some addones in it by default and ask the user on installation a fresh copy whether or not you want to enable it

Works like a charm.

So far, every website I tried it on worked very well, and the customization available is very nice: color, contrast, eye-strain reducing sepia tinting, white- and blacklisting websites are all available.

I am very happy with the addon.

This is best Add-On/ Extension for Dark Theme lovers. It works on all Websites.

Works great on almost all websites, I barely even think about the fact that it's on. The few websites where I don't like how it looks are super easy to mark.

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?