Ah! been waiting to write these babies up. As with a lot of new products, more so with those with big name companies, there has only been a partial truth in product reviews. The OnZa HO was hailed as a solution for high end / low cost brakes, not to mention the simplicity in brake pad adjustments and towing. This is true, to some degree.
The HOs are primarily of a post and slide design regulated by spring adjustment. The brake consists of a spring (Silver for left, Gold for right), dust cap , brake boss sleeve, and brake assembly. The brake assembly consists of the brake boss/post clamp, brake pad/post clamp and the post. Installation is easy enough and adjustments are simple as claimed. Each brake post has a set of four bolts (5mm), the brake boss, the boss clamp to the post, brake pad clamp, pad clamp to post. Set up was easy, tightening the bolts presented a mild problem. There wasn't much brake to hold onto to provide counter torque when tightening the bolts. Adjusting tow (toe?) was easy, once the pad is laterally in place, loosen the pad clamp/post bolt and make the proper ajustment, voila!
If using the "Chill Pill" centering with the spring tension is easy. The cable running through the "Chill Pill" is included with the brakes, one side with a catch and the other with an adjustable catch 'knob' (for a lack of a better word). The cable is thicker than normal brake cable so that the knob (adjustable with two 2.5mm) does not pinch through when tighened.
Aside from some installation hardships, the brake performance is outstanding. Through mud and moist conditions there was little loss of stopping power.
Be certain the brake bosses are tight or it is likely the spring tension will spin the bosses (e.g. loss of tension). Cheezy plastic dust covers. Poor frame/brake-brace/fork clearance for the pads. JUDY XC brake offset location flexs the brace forward under hard braking. This is an "okay" product for the money but an extra $60 could buy a beautifully engineered set of Avid Tri-Align II cantis. If a lack funds is the issue and you don't like the brakes you currently own (not trick enough), these brakes provide great stopping power but the design needs more work. Or you could tow in your brakes correctly.
After a few rides rust developed on the clamp bolts. If you are worried about this SRP makes a nice Titanium bolt kit that would easily remedy this problem. Aesthetics!, the bolts should last a while anyway.
If there is a Suntour-like brake cam (usully the rear)....problems. First off you cannot use the "Chill Pill" because the cam in most cases is used to remedy the problem with a bike lacking a brake cable hanger. A careful balance of spring tensions among the brake posts and cam is required to avoid rim push while braking. Another problem with cam compatibilty is that the thicker cable is not used. What this means is that unlike the "S" company's canti-brakes where a screw is available on one canti-lever to clamp down the brake cable the OnZa's require two catches, no screw. The adjustable knob has to be used in this case. With the wimpier brake cable the clamp tension has an increased probabilty of snapping a cable strand. Broken cable strands equals weaker cable, weaker cable equals imminent failure in expected stopping distance which could result in an unfortunate incident. Using a sheath over the point at which the clamping pressure is applied could remedy this problem.