I am not going to speculate on Zen~'s intentions, and it is not my place to say whether he is right or wrong. I generally agree that with the Z Atty Pro, it is not 100% necessary to use an insulator for the device to work, and work well. I do think the insulator is helpful, and removes one point of a possible problem for someone that is having trouble getting their wick/coil short free. I use other RTA's without insulators and they work great. The big fat tightly rolled 3.5mm wick is my preferred wick, as it does wick really well.
That being said, I currently have a tightly rolled wick installed with the insulator, and it is wicking very well. Plastic does melt, and if your bottom coil is too close to the insulator it will melt with normal use. I have learned to keep that first wrap at least 2mm above the atty floor for that reason.
My personal recommendation is to use the insulator until you are well versed in making a short free wick and coil. And I will always tell people that the manufacturer's recommendations should always be followed despite the fact that it may work in other configurations. Unless, of course, there is a valid safety reason that the manufacturer's recommendations should be ignored or contradicted.
