I haven't really used a Linux system in a long while. Last time I read up about ATI drivers for Linux was in a magazine, around 2007. It seemed like they were just starting to cooperate a little to release some drivers (though they were still crap). It's six years later now and frankly I'm a bit disappointed. Performance of whatever driver is automatically installed with Nadia appears to still be sub-par. The simplest of 3D apps can barely break 15-20fps at the best of times.
Granted, I'm using an old, pre-2009 mobile Radeon. But there must be some new options regarding drivers by now? The only threads I see here tackling the issue are a bit dated.