Interesting info.  The details of this report include enough information you could easily use it as a guide for your own testing.

Windows Vista and Windows Server 2008 Network Benchmark Study

Windows Vista and Windows Server 2008 include significant network performance improvements that can increase user productivity. This third-party benchmark study done by The Tolly Group compares network throughput and time-to-completion of several tasks when using Windows XP, Windows Vista, Windows Server 2003, and Windows Server 2008.