um...no, ATI cards have better shaders, ATI chipsets are actually really good, they just need to improve on their software/drivers and the companies that use those chipsets in their cards need to have them cooled properly. Before my X1900XTX fried, it was running way better than any card I'd ever used before (in windows).
In linux I love nvclock, if you don't have it and you're an OC'er then I recommend it.