Here are my latest discovery using Foggers V4.2 and V4.3
I have them both setup identically with 0.6 Ohms dual coils made of 0.6mm flat ribbon and Rayon wicks in a "Turkey stuffing way" with absolutely no wicking material in the juice channels. I use the same e-liquid in both.
V4.2 is quitter, tastier, cooler and smoother (less throat hit) vape experience. BUT, because, due to it's smaller chamber, the wick holds less liquid and I, occasionally, get a dry hit when chain vaping. This one is good for your first vape in the morning. It's capacity is advertised falsely, it can only hold 4.75 LM, that's 1.75 ML more then 4.3 - No big deal.
V4.3 is louder, tasty enough, warmer and harder (more throat hit) vape and it's larger chamber is capable of keeping up with my chain vaping. This is my "Afternoon Delight".
I vote for V4.3 because even though it can hold 1.75 ML less then 4.2. I like it better because that big deck allows for more building experiments and, in my opinion, the juice channel are just a right size to conduct juice flow efficiently if not obstructed by wicking material. The last, but not least, is that occasional dry hit in 4.2 is a "Deal Breaker" for me big time.
Those are my own personal experiences, take them for all they are worth. And, of course, YMMV.