If it was only in bright sunlight... Today I took the N800 as navigation device on a hiking trip. It was cloudy all day but nevertheless it was nearly impossible to read the N800 display.
The missing daylight visibility of the display is the only thing with the N800 that really sucks - big time.

Imo this is the most important improvement. Much more important than the keyboard or the internal GPS. I'm wondering, why this isn't even mentioned on the Nokia N-Series webpage. The Nokia marketing guys mostly focus on the GPS and the keyboard.