The kick makes your device work the same regardless of the resistance of the atty or carto you use. I reads the resistance (ohms) and adjusts itself to deliver the same power (watts) through whatever heating element you choose. It also self regulates- meaning it adjusts for loss of battery power through the life of the battery.
It's a good thing to have- I have two. If you don't jump around too much from juice to juice or heating element type to heating element type, it is a fantastic device. Otherwise, you adjust it but that isn't too hard. It works in certain pv's that are listed on the evolv or super-t website, some people make them work on other devices but that voids the warranty (how do they know?).
PM me if you have other questions.