Just to add that the 702 can record to an external FW HD only if connected to an external power supply.
That is not true; the 702
will record to an external FW HD without an external power supply. First, this is what Sound Devices says on the subject:
"FireWire Bus Powering
The six-pin FireWire port on the 702 provides power for bus-powered FireWire drives. The following conditions should be observed when connecting to bus-powered drives.
• Bus powering a drive requires external DC powering of the 702. The 702 cannot operate buspowered drives from an attached Li-ion battery.
• When recording in realtime to bus-powered FireWire drives the XL-1394 FireWire Power Filter is recommended. This fi lter network isolates the electrical noise in bus-powered drives from the 702.
• While hot-swapping FireWire cables is possible it is strongly recommended to attach bus-powered drives with the recorder turned off. "
I realize SD says "the 702 cannot operate buspowered drives from an attached Li-ion battery," but it works. In fact I just tested it on my 702. Now running an external HD will pull down the battery pretty fast so I'd run the 702 with both internal and external batteries.
Heed the don't hot-swap FireWire warning. Apparently hot-swapping
sometimes fries the 702's FireWire circuit resulting in an expensive repair.