I coat so I can push softer lead faster than I could before. I can take range scrap to speeds that required clip-on wheel weights before. Range scrap is easier to find, cheaper, and renewable.
And..... I like the colors. I could care less about the smoke. I shoot BP pistols often, just for the smoke!
For speed, you can't beat a Star though. I still use regular lubes sometimes. It is not always convenient to spray or even shake-n-bake when I want some boolits prepped fast, and the Star is fast.