Most of my stuff what I have used in past months are hybrids (Zenesis, Diablo, Silver Dog), or 14500 mechanicals (SturmMod, GP Piccolo, Golden Mod) - but I was lacking 18xxx battery mod. So I bought K100 because a.) it was cheap b.) i heard lots of good things about it.
For it's price - the main thing, it fires well. There are no springs between battery contacts to atomizer. And it fires well, even with chrome plated contacts, which you can easily sand. There are many high-end mods, even hybrids, that perform much more poorly than Kamry K100. Without tweaking, I had 0.38v drop to ~1.0 ohm coil with fully chargerd AW IMR. After sanding the contacts, 0.27v drop. Impressive.
Build quality - Solid. Far better than my previous chinese mods.
Threading - Very nice.
Locking ring - Very nice, and it's reversed. It's nice feature, because you don't open your bottom cap accidentally so easily.
510 connection - No problems with my attys. Could be adjustable, though.
Firing button - Feels firm, even a little stiff, little bit long travel but quite ok. I have experienced much worse.
Looks - Well, not the prettiest but quite ok. Empire Mod-clone (not big fan of clones). 16-20mm atomizers fits quite nicely. In 18350-mode this looks best, quite stupid looking imho in other modes. And only color that I like, is brown.
Conclusion - really worth it, buy it