I have a genuine KFL+, R91, and an EHpro clone. The one I like the least is, oddly enough, the one everyone seems to say is the best clone. I don't have the Hcigar and the Tobeco versions, but I'm happy to compare the ones I do have.
R91
I had problems with my R91 out of the box. I had to replace the insulators in it to get it working without shorting out. The upper and lower chimney seem more like nickel plated brass than stainless steel, in fact I'm pretty sure it is. Not worth the price imo. I'd stay away from this one unless the adjustable center pin is a necessity for you.
EHpro
The EHpro is very nice. The machining quality ranks right up there with the genuine. The draw is the tightest of the three. It's not so tight that I feel I need to drill it out, but I did completely remove the adjustment screw. It is 100% stainless steel, but it seems to be a slightly lower grade than the genuine. Not a big deal. No complaints with this one, just some comparisons.
Genuine KFL+
It's the real deal. Nuff said.