Here's the edited reply... very nice note from their Cartography Department. Score another for Garmin. Now the note:
Thank you for contacting Garmin.
Let me preface this by saying you have caught us at a weird time...they are phasing MapSource City Select out and going totally to MapSource City Navigator (we'd suggest one of those for this model).
Matching versions and flavors of Navigator and Select are similar products with compatible Garmin units...there are some differences in the guts for routing. For example, Navigator is more thorough in roundabout guidance. Select will get you through it, but it won't be as informative. It involves things like that. In the big picture, they are very similar products, but there are some differences in the guts.
Something in Select's favor at times...Select's map templates are cut smaller than Navigator v7's. So you could customize the map set a bit more with Select than you could with Navigator (rather than, say, loading all of southern Georgia to get Atlanta as you would with Navigator with Select you
can select just Atlanta and save memory for other areas).
I would very, very strongly recommend reading about City Navigator North
America v7 (note again the v7 products are on DVD) and using the MapSource Map Viewer to see the basic detail in it (be sure to zoom tightly and click the "more" detail button) starting at:
http://www.garmin.com/cartography/mapSource/citynav.jsp
(Basic map detail you see with it as far as the roads, streets, etc. will be
the same as what would come in Select North America v7.)