Hey Papa, I have no experience with a Kayfun V4, or a Lemo or Lemo V2, but I've given up my Kafun V2 for the Erlkonigin and, heaven forbid, the clones. It's just a straight forward build and works great with a 4/5 wrap at 3 mm, 28g Ni and KGD cotton on my sx mini M at about .07. Quorax is the dude and you can see his builds and tips on other threads. Works great for me. Fewer parts and heartaches IMOP. I actually went there prior to TC and loved it with Kanthal. A clone from FT would be a quick and cheap way to try it out. 2 cents please.