I've found that both FW and TFA skittles knock off flavorings are pretty bad. One was better, but I think I'll just toss both of them. I have enough good flavorings, that trying to correct bad ones is a waste of my time.
Some that are destined for the trash heap:
TFA granny smith tart apple
FW Skittles type
TFA rainbow drops
FW plum (prune was more like it, nothing tart or delicious in that one)
FW tall maroon soda (Dr.Pepper knock off) Not even close for vaping (might be fine for candy making, but i have heard form others that it really isn't)
Capsicum - I'll keep this around for pranks, but there is no good use for vaping, unless you enjoy scorching your entire respiratory system.
TFA? Jalepeno - Not much of an improvement over capsicum, and it seems to be an oil as it is a thin green layer over clear liquid. Use for food, not juice.
CAP energy drink - Never had energy drinks, so I thought Id give it a whirl. NOPE! It's like cherry vomit. Y'all have fun with this at the landfill.
TFA Grape juice - didn't get anything grape-y from it. such a dissapointment.
TFA Lemon - Again, total weak sauce. No level from 3-20% gave me anything remotely close to a satisfying lemon flavor.
TFA Raspberry - too perfumey. Might work well in a candy, though.
I'm sure I have others that will be tossed or re-purposed for food consumption, but the above were no good for vaping (for ME, your mileage may vary).