If you can build a coil on an Evod, you'll have no trouble at all on the Kayfun - it's so much less fiddly.
I've got two KFL+s, and they're amazing. Very thick, rich vapour, and they taste brilliant. Well worth the price.
They do leak slightly (e.g. when you fill them, although there are knacks to avoiding that, and if you leave them on their sides). They have polypropylene (or whatever it is... the one that reacts with certain juices) tanks, though they come with a steel version too (not sure how practical that is, not being able to see the juice level, but no doubt you can get used to it). It's also slightly annoying not being able to fiddle with the coil without draining the tank.
But other than those minor quibbles, I'd say do it without hesitation.