I've found it runs slightly slower, but not enough to be annoying. I'm processing Canon 1DsII files (16 megapixel) without any probs.
What IS $#@(*& annoying is that CS2 pulls window focus about 3 times as it loads. If you're a multitasking freak like I am and routinely switch to something else while you wait for software to load then it really pisses you off.
