When I zoom in on something with the OS map it becomes so pixelated it's difficult to make anything out – I assumed the graphics would be vector based. I'm going to do much, much more on road than off, so don't need all the detail of an OS map, I do need simple turn by turn directions and a big button that says "get me home" :-) – I'd come across the comparison Andy_G has linked to and think the more 'car like' maps of the city navigator would be easier for me to follow.
I realise it's my own fault for picking the wrong bundle. I don't drive a car, but got a Tom Tom out of the box and could work out how to use it immediately and kind of assumed the 800 would be similar.
Perhaps I'm just having a senior moment or two, but I don't have a problem with computers or cameras, just Garmin Edge 800s Still, if I get it worked out the thought of not getting lost on rides is very appealing (I have got a s*** sense of direction).