The 580 is going to be a little quieter, and is faster. I have owned both and I didn't hesitate to upgrade to the 580 for the noise issue alone. Overclocking the 480 to match the speed of the 580 will only make it that much louder. The 580 is actually pretty quiet. PNY is a good brand and better yet, they're an American company.
It's hard to beat the price of the 480, though. If you are an enthusiast, like recon, who knows how to set up your case with good airflow directed at the video card, then the 480 is worth it. It's basically the equivalent of a GTX 570, but with more memory.
In fact, you could consider a GTX 570 at about $280:http://www.newegg.com/Product/Product.aspx?Item=N82E16814130613