Had me radius for 3-4 weeks and it has not missed a beat, and even though I've not used kayfuns in over a year, it actually made me want to look at kayfuns today, got a black kayfun v4, and loving a good kayfun vape again, if they make a stealth radius, I would be tempted to get it, just because I think the black kayfun would look awesome on it.
Also who ever said about not having to go low on builds to get a good vape, was spot on, have been using builds between 0.50 and 0.80 ohms for a while, but did a 1.2 ohm coil on the kayfun, and getting just as good vapor, but better flavor, but that is probably down to the kayfun not the build