The foreward (or was it an afterword?) in the edition I have on my shelf has quite a bit on how she produced it, and it is very interesting.
It was a process of very intensively studying and comparing all existing English translations she could find, using the Carus Chinese character-by-character translation as a sort of rosetta stone. While of course using her own literary sensibilities to phrasing too, as an author.
I could easily believe this would result in a product that is a more faithful conversion to English than many translations. It's interesting to think about how this in some ways can combine and synthesize various subjectivities over time in a way that you actually couldn't do if you read the original language and believed your "own" take on the original translation was the "correct" one!
In the forward she also names a scholar of the Tao Te Ching (who was able to read and study in the original language) she had been in communication with for advice, who had complimented and supported her work. (although of course LeGuin takes responsibility for all errors or misconceptions!)
I wonder if any other conversions/renditions/translations have been done of other works through similar method, I guess if any they would be to other ancient texts (the bible?) that have had many translations. [I don't think we really have a good word for what she did, since it's not really a thing done much, so I understand the poster using the word "translation" although OP does not and just says "English version by" -- but we jump to figure that means a "translation", right?]
It doesn't look like the foreward (I think unless it was an afterword, I don't have the book in front of it me!) that discusses this is included in this online (and presumably copyright-violating pirated?) copy? If you can find a copy (pirated or not I don't judge) of the foreward, which isn't very long, where she describes her process, I definitely recommend it! (Or is it here?)
Something about the process seems especially interesting to the HN crowd to me... I want to say it's perhaps about "abstraction"?
If you were to take Le Guin's rendition and compare it with any other English language translations of your choice, it would be in the spirit of her project, and I'm sure she would approve and think it would lead you to greater understanding of the work!