I use it on my Sulcata. I think its helpful, but not a must. I know it sure makes my tort look like a show piece! some will tell you that it helps reduce pyramiding, I don't know if its true or not, but I don't think it would hurt!
It isn't harmful and doesn't hurt the tortoise if used as directed, and whether or not it provides any benefit is debatable. I don't think it should be used as a substitute for some lack in husbandry, but I do use it for my own reasons and have for years.
Yes, that was a fascinating debate. I read almost the whole thing, almost word for word, waiting for someone to step in an correct the assumptions about some of the ingredients of Vita-shell. The main complainant twice stated that Lanolin is a petroleum product when in fact it is an animal product from sheep. He also kept referring to the possibly harmful effects of petroleum products in general. When I looked up "emulsifying wax NF" I learned that it is a vegetable product. Hmm.