The other day we were lamenting the fact that translations mainly seem to get noticed in reviews when people think there's something wrong with them. This makes sense, because most people can't really tell how good or bad a translation is, because not only would they have to know both languages involved, but they'd have to have a copy of the original plus the translation to compare them.
Of course, they could probably tell how good or bad the writing of the translation is based on whether or not it sounds like natural English, or if the characters have unique voices, etc. But in most cases the reviewers tend to focus on the story, the art, and maybe whether or not there are a ton of translation notes. Then, as I said earlier, if the translation does get mentioned, it tends to be something like, “I wish they'd left that title in Japanese and given a note instead of translating it,” or, “I can't believe they used a Southern accent again!”