Louder, hotter and more power draw than the 660, but you won't get a 660 for that money. And you'll see the difference if you play any games that have lots of big textures to load, that 384 bit bus will move data around much quicker.
Intel i7-2600k with an XSPC Raystorm water block, 4x4GB Corsair Dominator, SLi Evga-GTX560Ti-448 FTWs, Asrock Extreme4 Gen3, Crucial M4 256GB SSD, Samsung Spinpoint F3 1TB HDD, powered by a Silverstone Strider+ 850 PSU in a Silverstone TJ-07BW case.
I'm not buying EK GPU blocks ever again. (One GPU killed)