I am totally satisfied with the Sigelei mini, to the point I bought a second. The easyness of battery change is paramount.
There are a couple of notes I would make.
First, the startup message, seen with fire button pressed while inserting the battery. It is not a garantee of the presence of a Yihi chipset, but certainty of use of Yihi firmware. I mean, the code that drives the microcontroller, is from Yihi. I have seen on Youtube a video of a Sigelei 50 Watt showing the option to turn on-off the touch-sensor, which is instead a feature of the IPV mods, not Sigelei. I must suppose that there is some form of "hybridation" between mod manufacturers.
Second note. The DC-DC mode, it has been reported in many reviews as "Mech-Mode", which in reality, is not. The regulation continue to exist, as the 30 Watt limit, even in DC-DC mode. The difference with PWM mode consists in the fact that the Sigelei mini, in DC-DC mode is incapable of down-regulation; the minimum voltage provided, and shown on the display, is the battery voltage minus the forward drop of the Schotthy diode, 4.2 - 0.45 Volt. So, it starts with 3.75 Volt, and the minimum wattage depends only on the atomiser resistance. The advantage of DC-DC mode is seen with liquids and coils that provide muted flavors with PWM drive.
In any case, the atomiser, depending on its resistance, will see voltage partialisation (PWM) only at the lower end of regulation range. With a 1.8 Ohm Aspire BVC, there will be no PWM signal, even in PWM mode, above 8 Watt. With 1 Ohm coil, there will be no traces of PWM above 15 Watt. With an old 2.1 Ohm BDC clearo, I have no PWM starting from 6 Watts. The 0.5 Ohm Atlantis, on the other hand, sees PWM for almost all the regulation range.
Other things good about the Sigelei mini? It is a BOX! I loved from day one the Innokin MVP 2 because of its prismatic shape; I know it is matter of personal preference, but I don't like curved box mods. I have the Sx mini but -aside the wonderful electronics with its 12 bits DACs- I felt defrauded of one corner, essentially being it a box with three corners. Joky note at the end...
Enjoy the Sigelei 30 W, it is an excellent mod for the price. In use everyday for the durability test, now...