I do edit on my powerbook 1ghz 768RAM HD fiwire 200.
Depend on what you ant to do. Its no problem but if you use to work on a station you might think about the speed.
Quite slow on a powerbook.
Better max the ram and a 128 graphic card. and firewire 800 , using firewire 400 for deck.
you could have nice workflow with this config but if you have to cut some TVC and client is in a hurry, prefer a station.
At work I’m running a G4 DUAL CPU 1GHZ 1G RAM and a RAId 0 scsi and its twice faster.
U still can make RT with your powerbook and if you dont have to much software or other stuff on your machine it should be fast enough to produce good professional work.
Anyway i do all my freelance job on my powerbook and i bought a pc to encode file to mpeg2 in batch list or render AE files so i could keep working by the time. Well i’m living in china and a PC is about 4OO EURO , so this is why.
hope that helps.
cheers