Hi, i'm finally going to start backing up my files now. I need to buy an external HDD i'm trying to decide between a USB 2.0 and a firewire drive. Apparently USB2.0 has faster speeds than Firewire 400 (using it with macbook, only have firewire 400). Why should i pay extra for a firewire drive, they seem to be more expensive?? Is there something better about firewire drives i don't know about??