I have a N810 and a N800.

On the N810 the dpad is very difficult to navigate with - the short side scrolls presses are too think for using thumbs or fingers - have to use fingernails (and I am a thin guy with not too thick stubs of fingers either).

The N800 dpad on the other had is much better - firstly - better tactile feedback
and secondly the raised elemnts on the dpad allow you to "feel" the left and right presses without looking at it.

On the N810 the rectangular side press area and the middle button on th dbad are all nearly flush and hence cant make out the difference much by feel alone.