Trackball mice are thick, and inevitably got schmutz in the bearings and got slow. Then you'd have to open them up and clean them out. Trackpads were a great u

Trackball mice are thick, and inevitably got schmutz in the bearings and got slow. Then you'd have to open them up and clean them out. Trackpads were a great upgrade to laptops when they happened, even though at the time, excessive moisture screwed up the trackpad, to the point that I needed to have a dime handy to put my finger on for a half hour after getting out of the shower. (Source: I've used mac portables since the PB 100, including most of the major versions)