I'm not 100% on this because I can't find the exact thread I read this in but:
I believe it's faster using Firewire 800 if possible to do this transfer over the ethernet cord. Something about the Firewire can maintain a higher speed. If someone can check me on this it would help, but I'm pretty sure you should try Firewire 800 (maybe even 400, if unable to use 800).
Like I said, don't quote me exactly on this, but I swear I read a thread arguing the transfer speeds on this stuff a while ago on this forum.