MacBook Air (wikipedia): 12.8 in (325 mm) wide × 8.94 in (227 mm) deep × 0.11 in (3 mm) to 0.68 in (17 mm) high
XPS 13: 12.4x8.1x0.71 inches
Most Dell laptops are ugly and most Apple laptops are beautiful, but this specific Dell looks quite attractive. I also like getting something unique.
I'd believe that the Apple trackpad is probably nicer.