In terms of thickness, Apple's 13-inch MacBook Air has the edge with a 3mm to 17mm range compared with Dell's 6mm to 18mm spread. At a starting weight of 2.99 pounds, the Dell XPS 13 weighs about the same as devices from Apple and Acer, due in part to a lightweight and durable carbon-fiber base.
In terms of performance, Dell's Ultrabook is light-years ahead of Acer's. Granted, the XPS is equipped with an Intel Core i7 (Model 2637M at 1.7GHz) compared with Acer's Core i5 (at 1.6GHz), but all other specs were on par including memory (4 GB) and operating system (64-bit Windows 7 Home Premium). The Dell XPS 13 turned in a peak Geekbench 2.2 score of 7,457 compared with Acer's 5,657. Both systems had nagware disabled and Windows performance settings set to maximum. During our battery test, which disables all power-saving features, the XPS 13 delivered just 3 hours and 23 minutes.