Coxoc fuel additive?

Never tried it, but read a review about it recently in one of the Dirt Bike rags....
They said it was really good stuff.
Pro: You don't have to re-do jetting for infrequent high altitude rides.
Con: Expensive!!!
They recommended it for trips to the mountains, when you don't want to re-do your jetting, but they said it was pretty expensive for normal/ more frequent use.