Well, I got it. Of course Madvapes just got the EhPro clone in stock, which is the one I wanted. Argh! But here's the deal on the Boge:
I must first preface this by saying that, unliike *everyone else in the world*, this is my first Kayfun. So can't compare it to other KFL's. However, my thought was that either it works or it doesn't, and it does! Quite nicely, in fact. The threads were a little squeeky at first but that seemed to clear up after I took it apart and cleaned it all over with Everclear and a toothbrush, then gave it a hot water rinse. I was going to let it air dry, but the excitement got the better of me so I dried it with TP and blew out the parts I couldn't reach.
Another note I should add was that taking it apart out of the box was a pain. I had to wrap rubber bands around the different sections of the tank to get it loose. Very tight. But after the initial strain and cleaning all went well.
By the way, there is an O-ring above the chimney (in the top cap) just like the other versions, however there isn't one on the fill screw. No leaking so far, and I've been vaping on it for an hour or so. The side mounted airflow controller does use a hex key, which I was not crazy about but I figured it was probably going to be a set-it-and-forget-it kind of thing, which it is, and being on the side you don't need to remove the tank to make adjustments. Nice draw on half open, much better than my Protank2. I opened it up a bit further than half and that was fine for me and my current juice.
I had a coil already built and waiting to install, and had watched several videos on Kayfun builds just to be ready for its arrival. It's a 1.4 ohm microcoil with some sterile cotton wick. The flavor is excellent. Not quite as good as dripping onto dual microcoils, but still remarkably better than the PT2. Since my SVD seems to have come back to life for some reason (I banged it on the table and got the switch working again, for the most part), I've got the new KFL+ on there at 11 watts. I tried 12.5 and it tasted burnt so I dialed it down, and 11 seems just right. Vapor production is sufficiently cloudy and satisfying. Throat hit is also bigger than I'm used to with other tanks, almost as strong as dripping. Also unlike the PT2, No Whistling! Yay!
All in all I'd say it was an excellent purchase and I'm very happy to have it. Most of my driptips fit, and the extras included the short clear plastic tank (but not the large one), a hex key for the AFC, a tiny screwdriver and a bunch of extra O-rings. A very good buy, IMO, especally for me being on a seriously low budget.
One last thing - I didn't fiddle with it, but the screw/pin inside the 510 connection seems to be insulated with white delrin or plastic, possibly making it adjustable like the Russian's pin. Not sure about that and I don't want to unscrew it while the tank is full for obvious reasons. Maybe someone else can remember to check that before they fill 'er up, otherwise I'll come back and post after I've finished off the rest of the tank and can check it out.