Well, now that you mention it, I do notice that when I'm at work and backing up our various systems over the network, I don't really get 100 Mbps transfer rates--usually it's just a bit less, like 10 MBps instead of the expected 12.5 MBps--this is probably why. I guess it really could make a difference for large volume transfers over networks. I'm gonna try disabling this the next time I have to do backups and see if it makes a difference.