I don't like how translation is only unavailable when the browser "thinks" the whole site is in a particular language. What if there's a single sentence that's not? Or if it guesses the site's language incorrectly? No translation for you.

We need more control over the feature. Even just the ability to select text, right click, and have a "Translation" menu would be huge. Looks like there is such a feature, but it doesn't let you pick the language pairs, which is the most basic requirement of translation.