Like quite a few folks, I've been plagued by issues with Vista on a Gigabit LAN, namely seeing throughput that's a fraction of what it should be. I tried the fixes Scott Hanselman outlined in his excellent Vista Gigabit post to no avail. The Google gods must have been smiling on me yesterday because I found an article I had not seen before: Disable Vista network autotuning. In a nutshell, open an elevated command prompt and run the following:
netsh int tcp set global autotuninglevel=disable
I'm now seeing sustained throughput between Vista and other machines on my network in the neighborhood of 80-100 MB/s. From what I've read, none of these 'fixes' are needed when all machines are utilizing SMB 2.0, e.g. Vista <-> Windows 2008 or other Vista clients. Regardless, it's great to finally be able to utilize all of my LAN bandwidth after almost a year of frustration.