Is their shtuff (FA) any better than TFA?
You can buy the same exact flavor from 5 different company's, and they will each taste different, and require a different % of use to get the flavor your looking for.
TFA and FA each have some flavors that are good, and some that suck, just like all the rest of the flavor suppliers.
All you can do is try a flavor, like Caramel, and if you don't like it, .. try it from someone else.
Some require a higher % use to get the same flavor, and that may be important to you.
Admittedly, you can "kiss a lot of frogs" finding the flavors you like, but that's just the way it goes.
I've thrown away more that I've kept, after a solo 2ml test of each.
It's a process of elimination to find what tastes good to your taste buds.
I love Coconut (foodwise), and have tried 9 different company's ... nothing, no taste of coconut to me, no matter what % I use.
Yet other say you have to watch how much you use, as it's a strong flavor

..I hate'm
In the long run, buying flavors that you throw/give away is still cheaper than doing the same with pre-made juices.
Once you find your "good" ones, the price of juice drops 90% in costs.
Have fun in the "lab"