Regrettably, not so hot, using your criteria. Here are my ratings:
Screen: Passive monochrome (not greyscale), with all that implies.
RAM: Not cheap. Cleverly designed so that you can't even use the otherwise electrically compatible modules from other 1xx 'books to go above 4MB total. Max is 8MB (2MB on board + 6MB module).
Kybd: Not bad, all things considered.
Expansion: SCSI only. Has connectors for external scsi and floppy. No internal floppy.
Size/weight: Very nice; the lightest and smallest of the 1xx series.
Pointing dev: Trackball.
Battery: Finicky, always dead lead-acid. Impossible to find a cheap, working replacement.
OS: Can boot 7.x. It's a 16MHz 68000, so you can actually get reasonable performance running a light 7.x. Runs MacLynx ok.
I love my 100, but I can't use it as a true portable (I took the festering battery out to make it very light). With a scsi-ethernet connector, it surfs the web at a mighty pace!