The PowerBook 100 TrackBall diameter, handiness is far, far superior to the big ball series. I used the 100 IRL, but not any of the full size models. When I collected my first pick of the full size series PowerBook 150*** or handled the RAM limited PowerBook 100's contemporaries the ball didn't fall neatly, naturally under my finger. PowerBook 100 mid-ball is handy to the level of the buttons. I felt I had to raise my finger up farther and it feels clunkier.
Loved the smaller 100 ball so much I had no problems adapting to the PowerBook Duo series' smaller ball diameter. Recessed into the surface, all but, if not co-planar to the buttons, so I wound up absolutely loving the 230 which replaced the 100 in my bag. But I used the Duos almost exclusively Docked from the start, so the KBD issues never bothered me as I really only used KBD and TrackBall in the field.
That said, I'm a mouse/graphics guy.
Loved the smaller 100 ball so much I had no problems adapting to the PowerBook Duo series' smaller ball diameter. Recessed into the surface, all but, if not co-planar to the buttons, so I wound up absolutely loving the 230 which replaced the 100 in my bag. But I used the Duos almost exclusively Docked from the start, so the KBD issues never bothered me as I really only used KBD and TrackBall in the field.
That said, I'm a mouse/graphics guy.