Gamespot has an article comparing the shiny you get when using a Nvidia GeForce 7900 GTX SLI and an ATI Radeon X1900 XTX Crossfire. From the article: "All told, the barrier to entry is enormous; but once you're there and running your games at 1920x1080 with 4x antialiasing and 16x anisotropic filtering, any regrets you might have had about spending a small fortune will be thrown out the window. We're sure that one of these setups offers a better experience, however. The two could differ in terms of raw performance or the subtleties of image quality depending on the game. Either way, if you're going to lay down the smack for the best performance, we're going to make sure you get it."