I’ve used Millant-Deroux dark for about twenty years. It gave me a little more grab than most that I’d tried to that point and didn’t seem as dusty.
I won the Jade rosin on the chat a couple weeks ago — thanks again, Michael! — and only got around to cleaning the rosin off of a couple bows this morning to give it a go. I think I like it. I get the grab that I have enjoyed with my Millant-Deroux but with less of the very slight rasp that I sometimes hear in my tone. I think the Jade must be a little softer, because I had no problem at all getting through the shine when applying it to my bows.
I saw someone on a forum elsewhere say that it will turn your bow hair green, but that seems unlikely to me since my other bow hair has never turned black from other dark rosins.