Im a temperature control researcher, and can give you definite answers on this backed with evidence (see here for latest TC tests and a list of mods tested so far imgur.com/a/KQKCH1H). Please note that YiHi powered devices "tempearture stripe" and often exceed the set temperature, because they are based on PWM, which gives a wide range of temperature outcomes (they cant control the power, only distance between pulses), so its not flat like a DC mod. Any DNA powered board will be great (mirage, odin mini). Only geekvape mods with the Nuvoton chipset work properly, everything else seems to perform badly so far. Probably dont bother with vaporesso, their temperature control is some of the worst I have seen so far. Smok is actually really good, once you configure the TCR correctly. Probably avoid VooPoo because of an 80W limit in temperature control. Innokin is very hit-and-miss. Avoid DiCodes (this will shock many, but their 21700 powered Dani25 mod is a temperature control disaster, see empirical data I have published). Initial testing of istick mods has not shown great results, full testing coming soon. I havent tested cold steel yet, so no comment there.