> Most [...] PowerBook's are compatible with MorphOS

Actually, MorphOS supports only a miniscule subset of all PowerBooks. It even supports just a small subset of all PPC-based PowerBooks. Even regarding G4-based PowerBooks, only about an half is supported. What's supported most of are the Aluminum G4 PowerBooks.

> as shown in the list on the official MorphOS website.

Unfortunately, the requirement mentioned there with regard to supported G4 PowerBooks has always been misleading.

> the 17" PowerBook also gives me a full size keyboard, with number pad

I'm with Kronos here ;-)