I bought some Tasty Puff Rootbeer from the Shell station today. Not having any unflavored nic-juice, I decided to test-drive it with some pure VG. Mixed at about 15%. At this ratio, it still thinned the VG out quite a bit more than I expected. For me, it was very usable like this without any other additives. Obviously, no TH at all using nothing but the flavor and VG, but it wasn't bad at all. Nice root-beer-candy type of flavor.
The flavoring itself is a clear brown-to-tan-ish color. My only concern was when mixed, instead of turning a lighter shade and staying clear, it tuned into a somewhat milky white and opaque fluid. Reading posts about this type of issue, it doesn't seem like that big of a deal... but it still concerns me enough to probably not use this combo that much.
(currently, I'm almost dry and waiting for the mailman... dang holiday...lol)