...Those flimsy plastic fenders bounce around and rarely stay centered...
Actually the roadracers are not that bad, if properly mounted. The mk2 model is better than the first version and offers better coverage.
For me the only real problem with roadracers is that they do not fit to my Cervelo S1 bad-weather-bike. The fenders require at least 5 mm space between the tyre and the fork (front) or brake bridge (rear) for installation: my bike has less than that, even with standard 23mm Conti GP 4000S tyres.