I got one. It burnt cotton at any temperature. Messed around with it, it made wire glow bright red at nearly any temperature.
Sent it back for exchange.
Next one temperature settings did nothing. It was all wattage that controlled it. Literally, 212°@20w was no different than 600°@20w. 600°@75w was no different than 212°@75w. Messed around taking it to wattage with kanthal and forcing it to show the version. It kicked into something resembling temperature control. But it doesn't have dry coil protection, it will never drop the voltage to 0v no matter how hot it's getting, it will still burn cotton, it will still glow wires although not as bright as the first one.
But the 2nd one does sort of work, I just wouldn't trust it running a wick dry or with a questionable feed.
They weren't always like this, I saw a review video doing the dry cotton test and it dropped to zero. They either changed something or their quality control is complete crap.
I'd avoid it. I'll also avoid any more mods with the Sigelei brand.