For me (I don't have an n810, I have an n800) it was the spacing. It also just felt slightly uncomfortable typing (could also be of the location of the kiosk I was at though).

Edit: The more I look, the more likely it seems for me to be going the TMobile G1 route rather then AT&T and iPhone. Especially since my girlfriend is already on TMobile and she said we can get a family plan together.

But since I could also just tether it with the n800 and I can wait till the next tablet comes out then that would give me the best of both worlds. Haha the only problem is having to use one Google account (since I use two different ones for different purposes). I'm guessing you can't just log in and out?

Edit2: Haha and I wonder what Android phones will be out when I'm off the family plan.