I think you can go even further than that in what you say. The N800 and N810 are the same thing, except that the N810 has different 'peripherals' in the form of a slide out keyboard, gps etc. But deep down they're the same computer.

The N810 is much more like a modern Nokia mobile phone, whereas the N800 remains truer to the internet tablet concept (which, maybe, Nokia is having second thoughts about now). But, as we say in the UK, it's horses for courses. Some prefer the N800. Some will prefer the N810. On a functional level, there's going to be no difference -- same fundamental hardware, same operating system.

I think some geeks will buy the N810 but, really, for people like us there's no reason to throw away the N800. I already have a GPS unit and a BT keyboard, and not only that but I have the know-how and patience to make them work. If somebody lacks this knowledge, or this patience, and wants things to "just work" out of the box then the N810 is a good purchase.