The Tao that can be translated is not the true Tao.
Indeed. Moreover, it has been known for over two decades that the oldest extant version of the manuscript is the Te Tao Ching, not the Tao Te Ching. Best translation, bar none?
The implications of the discovery that the oldest version is actually the Te Tao Ching are significant. What had long been regarded as "the first verse" is actually "the first verse of the second section," and what had been regarded as "the minor second section on governance following the major first section on matters philosophical" is actually "the executive summary of the applications relevant to ruling princes" while the "Tao" section is actually the "additional appendix of philosophical material unlikely to be ready by a busy executive."
Mitchell's various translations are lovely poetry in their way, but inasmuch as he speaks none of the languages from which he is translating, they do have significant limitations.
Hope this helps.