eMap (2.73):
        Lighter and smaller, handheld style (probably need to get the impact resistant cover)
        Can use 8MB or 16MB memory cartridges to hold all Garmin map types except BlueCharts
        Has 14-hour battery life (based on just two batteries)
        Can be carried in the shirt pocket
        Medium-size screen
         50 routes with 50 routepoints each
        NO turn by turn routing
        Total 500 user waypoints
        Total 1000 map points
        Total 2048 trackpoints
        10 (reduced) tracks with 250 trackpoints each
        Has TrackBack feature
        Gives highway exit numbers
        Better base map, includes exit numbers and services
        Only water resistant
        No combo data/power cord, for use in car with laptop
        Requires different data/power cable(s) from previous Garmin products
        No control over backlighting
        Does not give numerical bearing and distance between waypoints
        Routelines from MetroGuide maps can't attach themselves ("rubberband") to street lines
        "Road lock" of present position to MetroGuide roads can now  be turned OFF or ON.
               NOTE: When the GPS position is some distance from any road, the "Error Circle" appears.

StreetPilot (2.07):
        Larger and heavier, dash mount, sturdier feel
        Can use 8MB or 16MB memory cartridges to hold all Garmin map types
        Has 15-hour battery life based on six batteries (need to buy power-adapter cable)
        Largest screen
        Turn by turn routing (with outside program)
        Total 100 user waypoints
        Total 500 trackpoints
        One Track with no TrackBack feature
        No highway exit numbers
        Waterproof (submersible)
        Standard (Garmin) antenna and power/data connector styles
        Control over backlighting
        Does not give numerical bearing and distance between waypoints
        Routelines from MetroGuide maps can attach themselves ("rubberband") to street lines
        "Road lock" of present position to MetroGuide roads can  be turned on or off
                NOTE: When the GPS position is some distance from any road, the "Error Circle" appears

G-III+ (2.04):
       Smaller Screen than the other two; slightly heavier than the eMap
       Internal memory storage limited to 1.4MB
       Can upload all MapSource maps except MetroGuide
       Longest battery life (about 20 hours based on four batteries)
       20 routes with 30 routepoints
       Total 500 user waypoints
       Total 2000 trackpoints
       10 (reduced) tracks of 250 trackpoints each
       Has TrackBack feature
       Gives highway exit numbers
       Waterproof (submersible)
       Standard (Garmin) antenna and power/data connector styles
       Control over backlighting
       Gives numerical bearing and distance between waypoints
       Has rotateable screen for horizontal viewing
        "Road lock" of present position to roads is not possible
       The "Error Circle" can be turned on or off

Interpretations:  The SP would be easier to actually use in the car, because of its dash mount and adjustable backlighting.  It is better when you have an idea of the route you expect to take and can preprogram the settings for turn-by-turn directions.

The eMap can be mounted with the (optional) accessory, and has limited turn-by-turn directions.  You can still set up a route with waypoints at the turns, and the eMap will provide distance to the next waypoint and direction of turn when approaching the waypoint, intersection, or exit number.

Since the SP does not have the TrackBack feature, the eMap is probably better if you just decided to go driving or wander around a city after parking your car (like the San Antonio River walk).  TrackBack could be used to find your way back by following the trail from the way you came. But then again, you (are) using mapping GPS receivers, so one way or another you should be able to navigate your way back without too much difficulty, as long as the starting point is recorded for reference.

The eMap has more total waypoints (500) and 50 routes of 50 routepoints each, the SP has fewer waypoints (100) and 20 routes of 30 routepoints.

If we remove the differences of the number of routes, waypoints, and tracking, it becomes a comparison of portability and mapping/directional assistance.  One could probably get by without the turn-by-turn directions in exchange for the portability of the eMap.  The fact that the base map on the eMap has exit information already that can be used as waypoints or GoTo points via the find feature will benefit the Interstate traveler.

The eMap Deluxe package with computer data cable and 8 MB card is about $235, and the MetroGuide CDs will cost an additional $125, totaling $360ish.

The StreetPilot  with computer data cable ($390) plus 8MB card and the MetroGuide CD "Package" ($170) is About $560.  The question is, do you get an additional $200 worth of features with the SP?  That would depend on what you're going to use the GPS for.

The G-III+ with computer cable is $345.  This GPS can upload all MapSource maps except the MetroGuide.

Send comments and corrections to: Jack Yeazel