I kept my N800 and bought an N810. I never use the N800 now. There are a lot of small improvements in the N810 that make it better to have. It is faster. The hardware buttons are placed better.

Most of the highlighted improvements are no big deal. The keyboard is not faster than the virtual keyboard. The screen is hardly noticeable as an improvement; the N810 isn't that great in direct sunlight. I find the N810's GPS pretty good, though. I am not interested in carrying a GPS AND a cell phone (essential) AND a tablet, so the N810 means I get GPS.

So maybe it is correct that the N810 isn't worth trading up for. Still, the N810 is better.