Extra buttons, so you don't have to use the touch screen.
I bought one whilst in the USA ($1200

). Having used it for 20k miles or so, I'd say that the extra buttons are pretty well superfluous. Even with my Gerbing heated gloves, which are huge and leave me the dexterity of a mutant with bananas for fingers, I was still able to use the touchscreen successfully. It takes a little practice - you press on the drop-down menu and then 'walk' your fingertip down the screen to highlight your selection - but it works pretty well.
I'd buy a 2610 without a doubt - best GPSR out there for bike/car only application (if you're considering using it for aviation or marine use, look at the 276c).
Vastly better re-calc time than the SPIII and much more user-friendly hardware & software. You're also not tied to Garmin's own brand data chip - it uses CF Cards (276c uses Garmin chips IIRC).
Oh, the Nav II does have an extra screen display (sort of Direction Finder compass thingy). Not sure if anyone else uses it, but I've not found it of any value...
Exec Summary - 2610 Good - NavII not worth the extra dosh. Others' experience may vary etc...
Mike
