At one time I saw ZERO G brakes EVERYWHERE, on everyone's bikes. Then they just began to disappear. I asked some of the former owners and the consensus was;
it was an overpriced, single pivot caliper that couldn't deliver the stopping power of dual pivot caliper AND they would never stay centered. Thus they went away.
Well, this doesn't represent the reality of the market for Zero G brakes. As a distributor I have different figures because I base my analyses on hundreds of sets and I keep in touch with a high percentage of customers.
I do not agree at all with the stopping power, this is completely wrong. I have some customers for which I setup the bikes who complained because the stopping power was too strong (on GSS, NGTi, GSL).
What is true is that you need a professional setup of the brakes. If your brakes are old and need to be checked, I personally look after the European market, and Ted the US market (I personally keep the brakes for less than 24h and ship back with the updates that you've chose on my website velo-perso.com).
What is wrong also, is that on versions after 2010 you don't need to center the brakes all the time. They auto center ! The initial centering operation is enough, except if you change the wheels, because all wheels are different (not centered exactly the same way) and you may have to make a small adjustment of 1mm or less.
So, that's true that some customers have decided to come back to standard brakes but it's the same for many other products, not only Zero G brakes. These customers have probably not tested the 3 star after sales service that I'm supplying in Europe and decided that Zero G brakes should be setup exactly as they setup dura ace brakes... but for a hundred grams saved they should make the effort to understand the specificity of Zero G brakes.
You cannot imagine how many customers are using the spacers of factory brakes... which shouldn't be used if you want the brakes to be auto centered.
You must use Ciamillo seat stay and fork spacers if you want to protect your frameset.
As of today we have many customers who are already riding 2 different Zero G sets. Ted and me have observed this year that many of them have bought a 3rd set !
So, I agree that Zero G brakes are not a mass market product. But they are definitely an amazing product for specialists who want to setup the best bike that it's possible as of today with a light weight and great stopping power.
Ted and me are focused on the development of new products that will enlarge our markets. We are aware that the Zero G setup is more difficult than the average, and we expect supplying a crank that will be easier to install than the average.