General GPS Comparison Guidelines
One of the first questions to settle is whether you need just the navigation function, or all the useful points of interest (POI) information. If you travel a lot, the latter POI database will be useful. Other things to consider are whether you need voice-activated controls whether you need Bluetooth capability; whether or not you desire to play games OR view photos on the unit; etc. It is possible to break down Garmin units by price range and then look at the devices in each price range.
Low priced devices (less than $200) usually have a 3.5 inch screen size, although wider screens are becoming available. All of Garmin’s devices feature excellent navigation based on Navteq’s map database, although whether you get 49 states or US-plus-Canada will depend the model you choose. Other standard features are “Where am I?" which tells you with the push of a button your current location and nearby emergency services, an MP3 player and photo navigation. Bluetooth, Traffic Receiver, MSN Direct and FM Transmitter are options that vary from model to model. Some models such as the 205W, 265 (including variants), and 275T come with lifetime traffic information from Navteq. The higher end models tend to drop this in favor of the Traffic Receiver.
Medium priced devices ($200 - $300) have pretty much all the features of the lower end devices. in addition these devices tend to add either a lane assist feature or a multi-mode navigation feature. These are generally in a 4.3 inch screen size form factor. Some of the devices add a 3D buildings feature, photo viewer etc. MSN Direct, Traffic Receiver, Bluetooth, and FM transmitter are once again options. Garmin Locate, or “where’s my car?" feature is added in addition to “where am I?" which automatically records the spot where the device is taken off the mount.
High price devices (more than $300) are generally differentiated from the others with the inclusion of a voice-activated interface. The speech recognition makes it pretty much the best navigation software around (for not just Garmin devices but any GPS units, period). Although most of them are in the widescreen 4.3 inch screen-size form factor, the nuvi 5000 comes in an extra wide 5.2 inch screen size form factor. There are the options for Traffic Receiver, MSN Direct, and Bluetooth that tend to differentiate the these models.