And I still stand by it. The expansion slot is WAY more convenient, because it is always available, like it was originally built into the computer. Don't have to bring or get out an external drive and cable.
PCMCIA, PC Slot, CardBus are all names for the same friggin thing. Depending on which brand of Kool Aid you drink.
The PowerBook G4 has a Single Type I or Type II, CardBus compliant expansion slot.