Hey! I searched high and low for quite a while for a set of these brakes. They are incredibly powerful and have lots of adjustment -- maybe too much for some people.
I always thought they looked quite smart and seem pretty well made/nigh on indestructible. Very light too!
Made by Curve Cycle Components (hence C3), who also made cranksets (I have one but haven't tried it yet - 176mm) and most recently were selling titanium frames (one MTB and one cyclocross) via the web for a not absurd price, but don't seem to be doing much atm.
Cool, huh.