How to Buy a GPS ???

It's a great time to buy a GPS. The category has matured and competition from nav-equipped smartphones has helped drive prices way down. As a result

, you can get a capable stand-alone GPS that can do much more than just help you find your way for a lot less than you would have paid just last year. Still, there are several factors to consider when choosing the right GPS: Do I need a big display? Should I spring for a live traffic subscription? How about voice control? Should I even bother with a GPS, or can I just use my phone? H

ere's what you should consider when navigating the GPS market.

The Basics: Screen Size, On-Board Maps, and POIs

Screen size is an important factor in choosing the right GPS. The current sweet spot for displays is 4.3 inches, with the majority of models on the market hitting this mark. You can typically save a bundle if you're willing to settle for a smaller display: The excellent, Editors' Choice 3.5-inch Garmin nüvi 265T rings up for about $120 these days. On the flip side, if you have trouble reading small text, you may want to opt for a larger unit

like the Magellan Roadmate 1700, whose bright, brilliant 7-inch, 800-by-480-pixel WVGA display almost guarantees you'll never have to squint to read a street name. Remember though, the larger the screen, the more of your dashboard or windshield space the unit gobbles up. The 5-inch screen on the TomTom XXL 540-S is a nice compromise since it's thin and not terribly unwieldy, but is large enough to display easy-to-see type and graphics and ensure accurate on-screen button taps.

Virtually every GPS you buy today will come with preloaded maps for the United States—some also include a combination of Canada, Mexico, or Puerto Rico too. If you need additional maps, you can typically buy them from the device manufacturer and download them via PC or sideload them on an SD card.

Since construction is inevitable and roads are constantly changing, keeping your maps up-to-date is also important. Larger vendors such as TomTom and Garmin include free or one-time-pay map updates for many of their devices. But some companies charge for each map update—and they can be expensive. Be sure to check the map-update policy before you buy.

Along with maps, every GPS comes with an integrated points-of-interest (POI) database so you can find, say, for example, the closest Chinese restaurant, Home Depot, auto body shop, or tourist attraction. POI database sizes can vary wildly, and each device handles searches and delivers results differently. Some are far-reaching and are intuitively designed to serve up logical, accurate results, while others have slim databases and leave you scratching your head, driving in circles trying to find a gas station. Some devices even integrate cellular radios to perform POI searches on the Web, so you get real-time results. (More on connected GPS devices in a minute.) The best way to get a handle on a device's POI handling is to read hands-on reviews.

Voice Control and Other Extras

A handful of GPS models let you speak commands so you can keep your hands on the wheel rather than poking at buttons on the device's touch screen. The most-capable voice-controlled GPS we've seen is Garmin's nüvi 885T. This $275 (street) live-traffic-enabled unit includes a wireless switch that you attach to your steering wheel to activate a listening mode, where it accepts voice commands for most functions. In our tests, the 885T recognized our spoken commands very accurately.

Voice control on the Magellan Maestro 4700, on the other hand, is very limited, and we didn't have much luck getting the feature to work correctly in our tests.

If you want some entertainment with your navigation, many devices include media players that support common audio, photo, and/or video formats for playback from an SD card. A much more practical extra feature, however, is an integrated phone interface, so you can connect your Bluetooth-enabled phone and access your contact list to make hands-free calls through the GPS, rather than wearing a clunky headset. While you'll find this feature on many mid- to high-end GPS models, not all devices support all phones. If this feature is important to you, check the manufacturer's Web site to make sure your phone is compatible before you settle on a device.