I'm with you on that; the stylus is great for xournal and other apps requiring fine-grained control, but should never be required for OS or generic UI functionality.

I finger my tablet a lot, but am often annoyed by UI elements that make it harder than it should be.

One (hardware) idea for finger-friendliness is the bezel angle. If the N900 had a shallower angle (same depth) bezel around the screen, fingering the edges would be much easier.