Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Essentially useless unless you buy mapping software for $130.

I'm a smart guy, but even I got fooled by this one. Although the product description states that the device comes pre-loaded with a maps of the U.S., it contains data only for US Interstates and major US Highways (not even all of them). Furthermore, the built-in maps are of such poor quality that this device is essentially useless out-of-the-box. Garmin designs their products so that only their proprietary maps will work on the device, so you have to buy them. Add $130 plus S&H for maps to whatever you expect this device to cost you. I couldn't be more angry about my purchase.