I'd say the N810's GPS is close to useless, it never locks anywhere near quickly enough (frequently it never locks at all!). No idea what went wrong there, because all other GPS Nokia devices I've used work fine. For some reason they really messed up with the N810 GPS.

If you're looking for major advantages of the N810 I'd say it's the physical keyboard, the more sun-visible screen, and the generally more "sexy" casing.

If you don't want any of those things, then get the N800 instead as it has more memory card options and a built-in FM radio.