>>293388I don't nav by mine regularly. But it's a good double-check if you're not sure about something, and it's pretty cool to be able to dig up tracks from years past if you're in the area again.
>>293421CityNav has more trails (for OHV routes and forest service roads, anyways) than topo does. The topo maps are only updated every couple of years, vs. several times a year for citynav, so the "urban" data on citynav is more accurate. As more and more terrain in the backcountry is mapped better, the maps improve.
It's really nice to have the topo lines in certain situations. Rescued some flatlanders from a bad spot a few months ago, knowing our position relative to the cliffs and how much elevation change there was in the canyon was very good information for our decision-making that night. >Pic related.
Being able to draw lines and drop waypoints in Google Earth then push them into a few guys GPS's was very helpful for the sled rescue the following day.
>>293426The basemap in the unit is functional. Minimal, but functional. Try the free stuff, look and see if there's adequate coverage in the areas you play in. If so, hey, great.
I cover a *LOT* of terrain (registration stickers from 4 states on my sled right now) and having consistent map quality everywhere I go is important to me.
Any Garmin receiver with a data card is capable of taking additional maps; don't need to buy one with maps pre-loaded. I wouldn't recommend a receiver without an external data card (MicroSD for Garmins).