All of mine are clones; 2 tobecos and 1 ehpro. I don't have the new v4 though, as I heard that it might be a good deal airier than the KFL+, which I would dislike intensely.
As for the quality of the clones, it's hard to say which is best, really; I was madly in love with my Tobecos, but found the ehpro KFL+ for $25 at sweet-vapes.com, so I decided to give it a shot. The threads on the ehpro are harder to deal with -- using the segmented steel/plastic/steel tank, it's very hard to get the base off without loosening the bottom steel segment, though I never had that problem with my tobecos. Also, the tobecos allow me to adjust the screw in the 510 connector up or down without loosening the coil base; with the ehpro, if I try to adjust the height/length of that screw, it loosens the coil base, which mucks up the resistance. The ehpro seems heavier, which might mean higher-quality steel, but with the other concerns, I think I still prefer my tobecos.
Oh also -- the chimney is longer/taller in the ehpro, than in the tobecos; this might mean better "sealing" of the chamber, but I just find it tedious when I'm trying to put the tank onto the base; it definitely means that the parts are not interchangeable, so I'm glad that I got the gold-colored ehpro, to keep all its parts separate from the tobeco parts (though the chimney is just steel-colored on both -- the ehpro seems a duller finish, whereas the chimney on the tobecos is quite shiny).
Andria