If you're doing any video editing, the XPS 13 is the better choice due to its typically higher CPU performance. The MacBook Air is fine for basic tasks, but it can get bogged down with more intensive applications. The XPS 13 also tends to have a better screen, although the latest MacBook Air screens are quite good. I'd suggest looking at benchmarks for the specific CPU/GPU configurations you're considering. For just general productivity, the MacBook Air's integration with the Apple ecosystem is a plus, but the XPS 13 is a solid machine that can handle more demanding workloads.