It is great, but stick to the static theme generator for specific sites or it can slow them down considerably.
It is very noticeable on duckduckgo:
clicking a result link and then going back to ddg takes seconds longer with dark mode on, which is ridiculous.
The static mode cannot be used globally because often it doesn't work right (most video sites are broken), so the only solution is to manually set the theme mode per page (this can be done easily but the UI to do so is not very clear).
Dynamic mode should not be the default for high profile sites like duckduckgo with such a considerable impact until this is addressed, and the static theme generator should be improved such that it works with most sites.

Changes all websites to dark mode very reliably. There are occasionally smaller issues if pictures are in the background (text becomes hard to read).
Easily to revert to original. Very low performance penalty, which is worth to have all pages in dark mode.

It's a must to save your eyes! Some sites eventually break, however the extension can be easily deactivated specifically for those.

Works great and very customizable. The only problem is that it likes to theme content inside iframes even if the extension is turned off for both the site inside the iframe and the parent page.

works immediately, does exactly what I want, and has the best configuration settings! :-)

Desde que lo agregé al navegador lo negro se ve de color azúl oscuro, ¿que pasó?

Dark Reader addon has a serious memory leak issue. This problem is affecting users for quite a long time.