From the descriptions posted of measurements with Smok meters and other in-line meters it would appear that the iStick is using PWM. The same PWM that the MVP, Provari, ZMax, and Vamo uses, it's the additional circuitry that makes the difference in the final output to your coil, not PWM or duty cycle (misnamed frequency). (the cheap meters cannot accurately measure these)
PWM outputs a square or sawtooth waveform that then must be smoothed and filtered with capacitors and chokes, same as your computer's power supply takes 120 volts AC 60 htz and provides a flat 5 volts DC to the digital circuitry +-.01 volts and millivolts of ripple. It would seem these APV don't filter perfectly, wouldn't expect them to for the size and price.
That said I've found some tanks and toppers are more sensitive to the ripple in the output of some mods. I have some very old regulated mods that have a very poor smoothing and filtering, they will run some toppers very hot, have to turn them way down. Those same toppers will function normally on my MVP at a higher number, but will vape fine if I adjust to taste, not numbers. I bet if these were labeled Low - Medimum - High, everyone could adjust them to where they vape well.
I still vape a number of my old unregulated mod quite often, with a fresh battery they run hot for the coils I build. I simply pulse the fire button on and off while taking a draw until the 4.2 volt surface charge drops to the 3.9 volt range.
I plan on picking up one or two of these puppies once they are widely available, I have enough to hold me a few years, so no rush. It would appear these should run what used to be considered standard ohms, (2.5-3.0Ω) very well. Maybe break out some of my old 801 atomizers, although they ran 3.2Ω standard, but may still fire hot enough for me.
