I used the same Acera for a few years on my Pro Tour when I had a problem with the OEM Cyclone. It works far better than it has any right to. I only switched it out for aesthetic reasons when I finally had some extra pesos in my pocket. The SunXCD that replaced it looks the part, but seems to function not quite as nicely. The rear triangle on that bike is chromed, though, so it looks better.

The best widely available claw hanger for a modern derailleur is probably the one from Sunlite.