I have the Garmin 76CS with City Navigator and Topo.
The city maps are Navteq based and quite good. The computer based interface stinks, however. I can look up addresses easy using my Garmin GPS, but on the computer program it's a real hassle--you don't just enter "1800 Belt Line Rd, Mesa, AZ" and have it go there.
Garmin's topo maps suck.
They're acceptable viewing on a GPS (when you have either a blank background or Garmin Topo as your only options), but not much use on a computer screen.
There are many other Topo programs (National Geographic, etc) but they pull data in from the GPS and display your location on a computer. I personally like DeLorme's Topo program, with it's ability to have multiple draw layers (Like AutoCad or PhotoShop vs MS Paint). Unfortunately, you need too have a laptop running as all GPS makers have proprietary internal maps (which is why their map software is more expensive).
ò Compare Garmin Topo vs DeLorme Topo:
See this post:
http://forum.delorme.com/viewtopic.php?t=6418Garmin has two layers of Topo support. Garmin US 24k is just for certain national parks, like their description says. I didn't buy it and don't know what it looks like. Garmin US Topo is very low detail--I have it. Major details only; don't zoom in too far. See these posts:
http://forum.delorme.com/viewtopic.php?t=2574&highlight=garmin+topo+compareAnd with a picture comparison with Garmin and DeLorme:
http://forum.delorme.com/viewtopic.php?t=4455