I thought I explained what I meant about constant wattage, I don't think it's a sin to talk about it in connection with the XL and Kick. The "theory" is that you can set a wattage, say 9 watts, and a regulated wattage power source will work well for any carto or atty by regulating voltage to always get 9 watts. That also implies you don't need easy access to the adjustment pot or whatever. I was surprised at how many cartos and atties need a different wattage. I mentioned the case of the Turbo eGo Clear carto, not on the XL, but because it's 3 ohms, yet vapes very well on an eGo battery, around 5 watts. If you typically like 9 watt vaping, you find the ideal wattage on these to be maybe 5.5 watts. If you try to run one of these at 9 watts all you get is a brief "poof". So the "constant wattage theory" doesn't hold up very well, nor the use of a tiny trim pot that is hard to get at. There are some not so obvious factors at work in coils.
@Kat, I'm just trying these out now. How much vape do you get out of charge on those 600 mAh NiMH batteries, and what sort of atty do you use with them?