It's easy to find your way to the best GPS unit

was a tad reluctant to pop a GPS device into my wife's car for a recent trip to Portland. No, it's not because I already know how to get to Portland. It's just that I've always thought the best way to learn a city is to get lost in it.

By the time we returned to Seattle, however, I was a convert.

On the way down to Portland I was impressed with how well the device tracked our location. And if I declined to follow its routing suggestion, the unit immediately came up with a new set of directions, all spoken aloud in the computer voice of our choice. I soon realized I rarely even needed to look at the pretty full-color display, which is a good thing since the driver's eyes really should be on the road. Just trust the voice.

But what really converted me was when we were driving to find a restaurant in Portland. I could have found it without a map, but the GPS device eliminated the anxiety and took us by a far easier route than I would have chosen.

For me, that's the key thing about GPS car navigation. Once you trust the device — and my experience tells me they are trustworthy — they remove the anxiety when you're not sure where you're going. That makes you a safer driver and the trip more enjoyable.

So how to pick among the literally dozens of models on the market?

I took a look at devices from the three big vendors: Garmin, Magellan and TomTom. Each offers at least a dozen units with different features and price points. And it can be confusing trying to figure out just what you want without shelling out for more than you need.

The good news is that the basic features of all the devices are solid. If all you want is destination routing with easy-to-follow color maps and spoken directions, you can safely buy one of the least expensive units, which will set you back only a little more than $100.

You'll also find that all the devices make it surprisingly easy to find destinations and to keep those destinations in an address book. If, for example, you enter "Bainbridge Ferry, Seattle," the device is smart enough to take you right to Colman Dock.

Not surprisingly, extra dollars get you extra features. With so many models to choose from you can pretty nearly custom build a unit that requires you to pay only for the functionality you want.

For starters, more expensive units offer wider screens. Personally, I don't think that's all that important. Once you get used to these devices you'll spend very little time actually looking at them.

The more expensive units also include voice recognition that allows you speak commands. Higher-cost units also feature FM broadcast, which allows you to hear the routing directions through your car's sound system instead of through the device's built-in speaker.

Another higher-cost item is live traffic updates. Even most of the lower-cost units are "traffic-ready," which means you can subscribe to the vendor's service, which broadcasts information about traffic jams, accidents, construction delays and the like to the device; it then offers rerouting advice. Subscriptions generally cost about $10 per month.

Subscribers will generally find other services thrown into the bargain, such as weather reports and advisories about gas prices at stations in the region.

Garmin Nuvi 855

Garmin (www.garmin.com) is the leader in the high-end GPS market. The market is so rapidly evolving, in fact, that the Nuvi 850 I tested a few weeks ago has already been discontinued. Its replacement, the Nuvi 855, is priced at $499.99. A version of the unit with a built-in live traffic receiver costs $599.

The Nuvi 800 series offers a widescreen 4.3-inch display and high-end features, including speech recognition, FM transmitter, MP3 player and lane assist. Another feature I found especially helpful was a remote button for the speech-recognition feature, which you can attach to your steering wheel. Another interesting feature is the 850's "pedestrian mode," which will give you directions that optimize a route for pedestrians.

Garmin offers free lifetime traffic with some of its more expensive units, which cost about $700. And its traffic updates take place in real time rather than at specific minute intervals.

Magellan RoadMate 1440

Magellan (www.magellangps.com) focuses on the basics. With most of its units costing between $100 and $300, you won't find Bluetooth calling, speech recognition or MP3 players. FM transmission is available in some units, though not in the RoadMate 1440 I tested.

The $199.99 unit, however, offers a 4.3-inch widescreen color display. The unit makes it easy to enter destinations, and its routing is fast and easy to follow. Users will also find built-in AAA tourbook information on restaurants and accommodations.

If you want to move on up to the Maestro 4730 ($299), you can also have Bluetooth phone connectivity, lane assist and FM transmitter features. Also on the plus side, Magellan is providing its real-time Traffic Link service at no charge, though many units will require purchase of additional equipment to take advantage of the service.

TomTom GO 740 Live

TomTom (www.tomtom.com) appears to be targeting markets between Magellan and Garmin. The Go 740 Live I tested is the first TomTom device that delivers live traffic information. It's free for three months and $9.95 a month after that. The $369.95 unit does include speech recognition, lane guidance, Bluetooth cellphone connectivity and an FM transmitter.

I didn't find the GO 740 Live to be quite as accurate as the Garmin. On a couple of occasions it seemed to fall behind itself in warning me of upcoming turns, and on another occasion it didn't warn me not to take a lane that could have led me astray. Its traffic feature — which costs $9.95 a month — is updated every two minutes. But the GO 740 Live does deliver a lot of functionality for its price point.

Patrick Marshall writes the weekly Q&A column in Personal Technology.