Does anyone know if there is a loss of quality when importing videos from HD video camera to my iMac via USB? Now that there is only one FireWire port on the new iMacs the FireWire port is being used for my time machine backups. I only have firewire connections on my external hard drive so I can't use USB for my backups. I used to use the firewire400 port on my old mac but now I need to use USB? Any loss of video quality when doing so?