I have 80%VG in mine right now and wicks without issue. I also was running some 90%VG in it for the previous 2-3 days, again without problems. I'm running a dual clapton 0.3 ohms. The Griffin will handle high VG juice, just needs to be wicked properly. I have a good bit of cotton in mine, used the Sushi Roll method and tails about halfway down the channel. I don't have any leaks or dry hits. Unless you a defective tank or o-rings, leaking and dry hits are usually user error.