Since no one else has said it here : Welcome!

According to eBay the N800 is running ~$130 (used) and the N810 ~$185(used) I've seen deals on new 810s for ~$225.

Where do you envision using the tablet? Inside or outside ?

The only thing I envy the 810 for is the screen, which is better in bright sunlight ( 810 owners correct me )

The syncher for me was the dual FULL size SD card slots. Especially as I had a few SD cards lying around. If you have mini-sd already, then this is moot

As for the OSK on the 800: If I know it's a short message, or search term in google then I use it. Otherwise, anything in xterm or long posts like this I break out the BT kbd or the PC at home.

GPS: Well that's a tough one. There are a large number of threads here about the good/bad aspects of the 810's gps performance...

I personally dislike the All-in-one thing....invariably I break one part of it and render the whole thing DOA.

Any way, whatever you decide, goodluck