The Garmin eTrex Vista Cx is a feature-loaded GPS receiver that is great for use on the trail or for geo-caching. With a built-in altimeter, compass and microSD card slot, it has the capabilities to keep you on track in the mountain wilderness, or in the city. (Although with such a small screen, I wouldn't recommend it for use by the driver while driving.)

Nice small unit for really basic activities. The power point button, however, is a real headache. Also, I would suggest color unless you’re not going to use this much. Even after adjusting the tint, this thing is pretty hard to see in daytime.

I've taken the eTrex Vista to Big Bend National Park. Works well. The altimeter was accurate without calibration. Calibrating the compass was easy. The display is not hard to read even though it is not in color, and even in sunny conditions. I think that this GPS gives you the most for your money.

Easy to calibrate as long as you read the instructions I have no problems using this in Yellowstone as well as Yosemite. I did need to calibrate the altimeter after a while, but that is expected.

The Garmin eTrex Vista has some excellent features. The UI is very intuitive and easy to use. I found the little joystick control pretty user friendly too. The sunrise and sunset features are surprisingly useful. If you're staying on a trail, the unit can be safely used by itself to navigate. However, if you're going into the backcountry, I'd recommend using it conjunction with a good topo map. The topos available from Garmin are pretty good, but just aren't of a high enough resolution to be used alone. I keep this little guy in my glove box, and it's very useful for quick navigational checks while driving. However, if you're looking for turn-by-turn navigation, you'll have to spring for something a little more beefy. The available memory is more than enough to hold all the maps I need. All things considered, this is a great little tool.