A resistive screen and stylus for a system running a GUI with more than say, four, touch points (for me) on a tiny screen is just plain essential. Maybe nine points with less fat fingers than mine. Or maybe more if you could get your fingers surgically sharpened. Even on the N900 with the relatively large screen, there were apps that could be easily used with fingers (like the telephone), but plenty that were way beyond the precision of my fingertips (and patience), like gnumeric. It was nice to have a pocketable spreadsheet.