When we last reviewed the Dell XPS 15, we praised the notebook’s strong performance, best in class audio, and colorful screen. Now Dell has upgraded its premium 15-incher with Intel’s second-generation Core series processors and Nvidia GeForce GT 500 series graphics, which promise even better performance. The XPS 15, complete with a 2-GHz quad-core Core i7, 8GB of RAM, a 1080p screen, and Nvidia GT540M graphic. The Dell XPS 15 sports a matter silver anodized aluminum lid that doesn’t pick up fingerprints, but it seems a bit dull.