I like the TK in all its incarnations. Like all Fenix lights, the build quality is consistant and of a high standard. They arent the most powerful out there, but are more than enough for the likely use they will be put to. The '18 version, at least in my examples, would be the most ' neutral ' in its output. It sort of spreads like the '15, but incorporates a hotspot like the old 2,900, 3 x XML version. Some dont like the metal buttons, but they work, and dont get hot. Now, before this starts sounding like a Fenix love-in, there are a couple of things i would change. The cell carriers, while they work well, are a bit old hat. Why not move to the milled out battery tube like a lot of others have done? And with six outputs in the '18 version, why couldnt low be a real ' moonlight ' mode. Dont let these gripes put you off though, its still a real nice light. Cant wait for the 2020 version!!!