From Murphy’s Pack:
Pretty good, but sometimes bounces around a lot. I am using 2500 mAh Nickel Metal Hydride batteries and that helps a lot. I just updated the firmware from 3.1 to 5.34 and that gave me more screens with many more options, still I only really use the map and compass screens. The download speed is ok but not fast, it is serial at 115k baud but not USB speed at all.
Also check out this comparison:
Magellan 210, SporTrak and Garmin Vista