Well, from my personal experience with both, I would go with the 680. At these points, they are both so close in performance, it comes down to other features such as temperatures, noise levels, RMA/support, and power requirements. From my experience with the AMD 6990 and 2 6970s and 2 680s, AMD cards run much hotter, require more power, sound like airplanes taking off, and it took 7 weeks to get a replacement 6970. With my 680s/670s, they require much less power, are almost completely silent, run cooler, and the RMA service took less than a week to get a replacement. Once the performance differences are so mimimal, look at other qualities. These are just what I've experienced with both competitors. Hope it helps.