Garmin Edge 800 best map for cycling?

dombo6 Posts: 582
edited March 2014 in Road buying advice
Just got one of these bike GPS devices. The base map is pretty useless so i was wondering if anyone could advise what maps to get? I have the Garmin City Navigator Europe in the car satnav but it's licensed to one device map so cannot use it in the 800. I have downloaded a couple of courses, this year's Dragon Ride and a hilly route around the Surrey Hills where i usually ride - just to see how the thing works. Interestingly, even with just the basic base map in the unit, if i download a route from the unit onto Garmin Connect is shows up in incredible detail where i've been, streetnames etc.
Ideally i would like turn-by-turn road instructions for the road bike and possibly trail use for the mtb but road is key at this stage. Any advice much appreciated.