28 is too slow unless you push a VV mod to its max settings. It can even be slow on a mech mod if resistance is too high. I have a bunch of 28, and I still consider it only for the more extreme vaper seeking super-low ohms. In more regular 1.8-2.2ohm vaping, it's basically useless. 30g is much more usable for decent resistance numbers and speed of heating.
"slow" makes no sense....in a technical sense, since the resistance is lower, the amperage would be much, much higher, thus electricity moving through the coil much faster (which is why 28 works so well on mechanical mods also)
if you're talking about heating up time, i really have no idea what you speak of, as it is nearly instant on most everything i use, and on a mech, it glows as soon as the button is pushed (at an average of 7 amps to the coil)
i understand all the talk of wire temperature and whatnot, however, i've noticed that the only way the heat is any cooler using 28 is when the wattage is extreme much like on the mechanical mods, however, that's dealing with low voltage, high amperage....you lose most of the heat when it spreads to the wick....higher voltage i find strains the coil and makes more of a central heat that burns through juice....
simple way to experiment and see for yourself: take two atomizers, both identical, wrap a 1.4 ohm coil on one using 28 kanthal, next, attach the one with the 1.4 to a Zmax with stacked batteries, and the other to a mechanical......now the Zmax with stacked batteries disregards amp limitations in variable voltage mode, therefore it can actually surpass it's 15 watt power regulation limit by pushing 6 volts to that 1.4 ohm coil in VV mode, which would be right at 26 watts.
now vape that. it's horrible.
second atomizer up, wrap .8 ohms on it with the 28 kanthal, and put it on the mech with a fresh battery and vape it....22.05 watts and it's an amazing vape, hell even 29 or 30 watts on a mechanical is amazing (.6 ohm coil) and i have a strong feeling it's because of the weaker imput signal.