Thanks, that helps put it into perspective. If the main difference in the screen sizes is the height, then I imagine that the loss of a bit of screen height in the N900 is probably made up for by the fact that the N900 doesn't always need to display the window title bar and menu at the top (which the Z generally does when using the standard ROM/apps, wasting vertical screen space).

However, the recently announced LG GW990, with 1024x480 4.8 inch screen, also looks pretty interesting. No physical keyboard, but I wonder if the larger touchscreen would make an on-screen keyboard viable.