Dimensions and Display

• One of the obvious pros of the Garmin nüvi 660 GPS system is its compact and lightweight design, measuring 4.9 inches wide, 2.9 inches high and 0.9 inches deep, and weighing 6.2 ounces. Its spacious 4.3-inch thin-film transistor LCD color touch screen with white backlight provides crisp and sharp images, as well as text at a resolution of 480 by 272 pixels, making it easy to read and see your route information.
  
  

GPS Features

• One area where you may encounter drawbacks in relation to the features on other nüvi models is the voice functionality of the Garmin nuvi 660. While standard and advanced navigational voice commands are provided by the nüvi 660, the device does not accept verbal commands from the user. Standard navigational voice commands include, for example, "Turn right in 500 feet," while advanced verbal instructions include street names, such as "Turn right on Old River School Road in 500 feet."
  
  

Multimedia Features

• For those who like a multifunctional navigational device, you'll be happy to know that a built-in FM transmitter allows you to listen to audio files through the car's speakers on the nüvi 660. This is done by tuning the device and the car's radio to the same unused FM frequency. A drawback of this feature is that there are no external volume controls on the GPS unit.
  
  

Miscellaenous Features

• The Garmin nüvi 660 allows you to add up to 500 waypoints, or favorite destinations. Unfortunately, you cannot save any route data. While on long road trips, you may find the unit's seven-hour battery life an inconvenience, but with a car power adapter, battery life should not be an issue. The nüvi 660 comes with a high-sensitivity receiver that boosts satellite signal reception when the device is in difficult-to-reach surroundings, such as indoors or underground. Garmin's FM Traffic service, which provides updated travel information, including road construction and traffic delays, is compatible with the nüvi 660, but requires a paid subscription.