I haven't got the beta acceptance yet but I hope I will (hint hint) but I have been keeping and eye on the forum(s). I've seen a few post relating to network speed issue so I thought I'd through in a couple of tips that I've found useful recently.
1. Vista's auto-tuning network feture.
This helped with a live messenger connectivity problem (i.e. none) on one system and large file transfer times on another. Apparently this feature doesn't play nice with some routers (I had an older KCORP KLS-5810 at the time) and after some digging I tried this and it fixed the messenger connectivity issue and also improved file transfer times.
Try this: - Click start - Type: cmd - Right-click cmd.exe when it appears under Applications - Click Run As Administrator - Type the following: netsh int tcp set globalautotuninglevel=disabled - Press enter - Restart your computer
2. Network drivers
Make sure you have the latest drivers, I recently discovered that the version of the network drivers installed on my work laptop had a known bug which caused packet loss during large files transfers - exactly what I was seeing. The drivers were updated and file transfer speeds improved considerably.