Works properly, but causes substantial battery drain on Android. Had to uninstall and move my styles to Greasemonkey scripts.

Though the quality varies between themes, the add-on itself is superb. An absolute necessity if you like customizing your favorite websites.

Useful for custom dark mode in sites without it.

All of the functionality of Stylish without the shady data collection and selling.
It's also FLOSS which is a major plus.