Using GPS to Navigate City Streets?

[zombieman]

Ive never owned a GPS before but am very good with electronics. I've been thinking about purchasing a Garmin quest, Roadmate 700 or so, or maybe a GPSmap 60CS. I travel a good bit and its usally pretty random. My question is, When installing software on a GPS unit is it usally city select. Or can you simply install the entire Southeast US on the GPS and have all the streets in it just as a city map would? Im sure it depends on the memory in your GPS but can someone shed some light on this. I'm borrowing a Friend Garmin Vista that has all the worlds base maps on it and am also wondering this.... Do the majority of GPS come with these base maps on them? If you do install certain citys for greater detail does it over write the base maps? Im just trying to figure out if this is going to do what I hope it will. Thank you very much for any help.

PS. Im leaning more toward the Garmin Quest than any, simply due to the price and features.

[AKlopper]

The City Select maps are not limited to cities only. The detail might vary outside the cities for certain regions (the South African maps don't cover the whole of South Africa, for example), but in the US I suspect they pretty much cover everything.

The City Select maps are broken up into segments, and you can select one or more of these to load onto your GPS. The only limitation on how many segments you can load is the size of the memory on your GPS. The entire US mapset requires a 2GB memory card.

The City Select maps take preference over the basemap for display purposes, but the basemap is not overwritten and will be drawn for regions not covered by City Select.

I personally would never rely on the basemaps for routing purposes as their resolution is quite low due to the rounding off of positions required to include that much detail. The use very few points to represent roads, and those that are there are rounded off to positions that are noticeably divergent from the roads on the detailed maps. It is often quite disconcerting to zoom in from the base map to the detailed maps and have some roads change position completely... :)