Yeah, i have used it a few times. I have found the Additive to work Really well, but Tyre Warmers set to at least 60 Degrees C, are a must. The additive keeps very consistent throughout the run, and preserves the tyres...unlike Paragon FX II. It is sorta similar to Tweak, but i think it's better
This is on a Very Clean, High Traction, Smooth Track though.
I have used it in hot and cold track temperatures, with only good results. So i would say....the best additive on the market at the moment.