I own the M16-13ZER, an orange-handled variant meant for rescue purposes and the like. Second knife in this line I have owned (lost the first), and the whole line are fantastic general-purpose folding blades, whose safety lock feature does work as advertised. Good, sturdy, ergonomic feel to the handle, and a blade sizeable and the right shape to handle some more serious tasks without being a ridiculously large folder.
The only cons are generally the screws that hold on the pocket clip, and occasionally the ones that hold the handle scales on. Especially in the former case, they become loose very easily and require a very small hex wrench to re-tighten. Can become annoying. Otherwise, I highly reccomend these knives.