Well, you can still get a good vape off of a FV device, just like you could before you tried VV. You just have to be more aware of your atomizer ohms and such since that's your main source of "adjustment" then. As for why to go back to FV, I ask why not? I still use my Screwdriver on occasion, it's nice to have the small and simple PV in my hand once in a while and I still get a good vape from it. My GG is a whole 'nother animal, I primarily use that for the UFS (which I can't use on other devices), to take advantage of the adjustable draw feature or for 6v vaping with dual coils (which most VV mods can't handle this high). Of course, I am looking forward to the Kick for my GGTS
It all comes down to tastes and what exactly you're doing with it, I guess.