I just got my Buzz, and unfortunately none of the juices I currently have like high voltage. I've got a few from V4L, and just got 3 from Vapor Renu. In my situation, it seems the thicker the juice, the more it will handle high voltage. My Cafe Mocha from V4L is the only "thick" juice that I own and it still vaped well up to 5.2V. I probably could have went higher, but my atty gunked up and stopped working. After I pulled it off and cleaned it, it worked beautifully again.