Ok, my 2 cents...
Don't buy the n810 if you expect to use it as you would a dedicated GPS unit. The software is marginally adequate. I used mine along side a TomTom for about an hour (aftera 15 min lock time). The location mark would jump all over the place as I was driving, accuracy of streets was not as good as TomTom and it would do a weird zooming in and out on the map while drving.

That been said, I love everything else about the 810...as it was purchaced as portable computing device, not a GPS.