I had my favorite coffee flavor in it at first, but it wasn't pleasant. I removed that and put in a cinnamon flavor in, it's much better, but not as good as in a cartotank yet. The vapor production is quite impressive though.Baditude: Definitely give it a tank or 2 before you decide on the flavor production qualities. The wick needs a definite break in. Also, I find that bolder flavors work better in them -- I was able to tune mine for more delicate fruity flavors, but vapor production was lacking. Admittedly, I've only done a few of my more delicate flavors in one at this point though![]()