So what your saying is that some juices taste better when hot or cold. Thats true I agree with that statement.
HOWEVER, your argument is still that because some juices taste better at different voltages is ludicrous, since adjusting voltage affects wattage and vice versa.
Furthermore, Temp Control isnt "set and forget", and neither is VV/VW or even a mech. You build your coil to suit your vaping tastes on a mech, you play with the vv/vw on said devices, and you set your temperature on dna 40 boards.
The advantage is that you will get a much more precise temperature, and thus better control on a DNA 40, and since you keep said temp below, say the ignition point of cotton, you will never get a dry/burned hit. Which means you dont destroy your coil/wick setup, which means you donth ave to rebuild. It also means you dont fry your daily setup in the middle of the day.
Dont get me wrong, my prefered vape is still my subtank mini on my zombi. But I'm finding I enjoy my subtank mini with the nickel rebuilt head at 430*. No dry hits, and the vape is perfect ^^