I have a Garmin 2720 StreetPilot and now have the Oem NAV in my Coupe. The ONLY calling card of the built in unit from my perspective is the fact that it is always there and I don't have to remember to bring it along. It does allow for more enhanced tweaking of the sound system but this is not relevant to the question being asked here.
On all other usability counts the external unit wins hands down. With an external unit I can sit down at my computer before leaving on a trip and add in all of the locations I need to know about easily and then dump it into the NAV before I take off. I can plan out interesting routes and add those in as well. When I get back I can dump all of the tracking data back into my computers to examine it later on.
None of that is possible with the built in NAV. Adding in a new destination is a crude task at best with a very clumsy interface and there are no real routing options besides find the fastest/shortest path.
The last pieces that make the built in NAV a joke are a) the price for admission with a fraction of the features and b) the one time you need a NAV the most is when you jump on plane to a city somewhere else - there is no way to take your OEM NAV along. I pump mine Garmin full of the destination locations like hotels, etc and then immediately plop it down on the dash of the rental car. As soon as the unit knows where it is, stash the location of the rental car place so you can use it to get back when you need to leave.
I have never used TomTom so I can't contrast Garmin vs TomTom. I have hand held Garmin GPS as well (Vista HC) that I use when hiking so the ability to use my laptop/desktop mapping software and map sets on both devices is a big plus. I am very used to the Garmin user interface and find it quite trivial to use.
Map set accuracy and needs are everything so my comments are really on relevant to my own needs and experience. YMMV.
On all other usability counts the external unit wins hands down. With an external unit I can sit down at my computer before leaving on a trip and add in all of the locations I need to know about easily and then dump it into the NAV before I take off. I can plan out interesting routes and add those in as well. When I get back I can dump all of the tracking data back into my computers to examine it later on.
None of that is possible with the built in NAV. Adding in a new destination is a crude task at best with a very clumsy interface and there are no real routing options besides find the fastest/shortest path.
The last pieces that make the built in NAV a joke are a) the price for admission with a fraction of the features and b) the one time you need a NAV the most is when you jump on plane to a city somewhere else - there is no way to take your OEM NAV along. I pump mine Garmin full of the destination locations like hotels, etc and then immediately plop it down on the dash of the rental car. As soon as the unit knows where it is, stash the location of the rental car place so you can use it to get back when you need to leave.
I have never used TomTom so I can't contrast Garmin vs TomTom. I have hand held Garmin GPS as well (Vista HC) that I use when hiking so the ability to use my laptop/desktop mapping software and map sets on both devices is a big plus. I am very used to the Garmin user interface and find it quite trivial to use.
Map set accuracy and needs are everything so my comments are really on relevant to my own needs and experience. YMMV.