Ok, I admit, I bought one of these. (albeit at cost, not retail...thank god)
A little background:
I have been collecting knives for about 20 years. I started with Case, I had a (thankfully brief) Cold Steel phase, and eventually graduated to Spydercos and Benchmades and a few customs here and there. I bought this in a moment of temporary insanity.
I bought this knife on a whim because the owner was a customer of a shop i worked at. (If you have been to the Atlanta Blade Show and seen a Mantis knives mountain bike...I built that....It is a rebadged Mountain Cycle, a now defunct mountain bike company)
anywho...on to the review.
I EDC'd this blade for about a week. After that it went into the drawer.
Blade: S30V

Um....no. Just no. IF the blade is S30V then it has a bad heat treat. S30V shouldn't be that easy to sharpen. I have other knives in S30V and they sharpen just slightly easier than 154CM and ATS-34. The blade on this is just slightly more difficult to sharpen on my Wicked Edge than a 440C Cold Steel Prolite. (The last Cold steel I own)
Ergonomics: Fair at best. The nub on the liner lock (yes it is a liner lock, not a frame lock) is a little too pronounced or the detent on the blade is too deep so it takes a little more oomph than I'd like to open the blade. The liner locks the knife open solidly, but the fit and finish is a bit rough so because of the extra momentum the blade has from muscling it open the lock has a tendency to require, you guessed it, more pressure than I'd like to release it. Furthermore, the ribs on the front of the liner lock are a bit too pointed and there is no scale cutout to press it from the side, so after a few open/close cycles my thumb was sore. Let me put that into perspective...I am a professional mechanic, machinist and welder. I don't have dainty, sensitive hands. I will say that it is fairly comfortable in the hand. I say fairly because the multitude of G10 bumps give it a very strange, but not uncomfortable feel. But it also doesn't melt into the hand like a Buck 694 hunter.
Reliability: I only used it for a week and it didnt break, so thats good. But it was also a crap shoot as to whether it would come out of my pocket and open on the first try too, so thats bad.
Durability: See those neato-whiz-bang cuts in the frame? the first time this knife is actually used to pry something the knife will break there. The blade (i.e. the part that isn't in your hand) wont, the frame (i.e. the part that is) will. I dont know about anyone else but having metal that has just torn and is probably sharp in a tight grip in my hand seems like a bad idea. Hard use, my ass.
Usability: The multitude of g10 scales on the sides, the faux sawblade spine, and the aforementioned cutouts in the frame all add up to this: Good luck getting this knife out of your pocket in a hurry, as all of those gaps perform one function: They grab errant threads and seams and prevent the knife from being deployed in a timely manner. The virtually useless index finger notch on the blade means the actual useable knife edge is about 3 inches out of a 4" blade. The holes in the blade ensure that all of the pocket lint that the knife touches works its way down into the internals.
Conclusion: This knife is a (freak) show piece...or something like that. It is the embodiment of form over function. It is the polar opposite of an Emerson Commander (an ugly knife that is ugly because it works well) Now consider that the Mantis Chaos looks as ugly as it does, and it works even worse than it looks, and you'll get my point.
Anybody want to buy mine?