Buggy. It breaks text fields on some websites like https://stackoverflow.com/ (try to write a comment and delete some characters) and https://support.xbox.com/en-US/survey/storebail (try to type and delete some characters). It makes it look like your text is not deleted.

See this: https://imgur.com/isMR8Un

Translation is great but the extension is actually incredibly intrusive. The way it injects elements into the DOM causes some websites to break. There is also no option to translate after right clicking as the add-on claims. The Ctrl+Shift+Y shortcut also overlaps with other add-ons and there is no way to change it.

on sites where there is text input in the form, after entering text and scrolling down there is a ghost frame with text, which continues to hang regardless of the scrolling. I rechecked the entire arkenfox config on a clean profile until I found that the cause of this glitch is a *** deepl extension

Simply the best translation service out there.
However, this add-on is unusable: Edited text in textarea fields gets completely messed up when the add-on is activated.