The drive mechanism, however, is only part of the issue. The formatting software also determines the drive's abilities. I should also qualify my remarks by disclaiming extensive testing. I simply hooked up the devices, performed an hour or so of real-world activities and then arrived at some conclusions. USB is out of the question for video transfer so the lack of a USB port on the VST is irrelevant for FCP users.
Portability comes with a price tag.
There are a few things to watch in the set up of the mobile system. A less-obvious caveat is networking set up. Many times laptops will be used on a network and you might be set up to get your IP address from a DHCP server. While the drives draw power from the FireWire bus, it is not advisable to run the PowerBook on battery power while also powering a hard drive. You could barely make it from cruising altitude out of LAX to Arizona on a fully-charged battery.