The Surface Pro features a USB 3.0 port, while the Surface RT has an older USB 2.0 connector. The primary advantage of USB 3.0 is that it transfers data up to 10 times faster (up to 4.8 Gbps) as USB 2.0 (up to 480 Mbps). If you plan to connect external USB 3.0 storage devices (e.g. a hard drive) to a Surface Pro, speedy data transfer rates are a big plus. USB 3.0 also offers better power management, supports full-duplex data transfers, and is backwards compatible with USB 2.0. Bottom line: USB 3.0 makes sense on full-fledged Windows business laptops, including hybrids such as the Surface Pro.