If you've ever used data-derived GPS on your device, you know that the data connection can sometimes wane, and you're left wondering what to do next. But a data-less solution doesn't have that problem. When you are connected to your network, 'nDrive' offers weather alerts, route sharing, and support for Facebook Places and Foursquare.
Also, you can take the 'nDrive' GPS solution with you internationally, without needing to purchase data service. But international maps will cost you extra, above the already daunting US$49 pricetag. But if this is in lieu of a standalone unit, you're still getting a pretty good deal.
So what are the disadvantages? For one thing, 'nDrive' allows favorites, but it won't let you search directly from your contacts application. Secondly, the U.S. map alone takes up 2.3GB. And finally, additional maps are expensive, e.g. the Mexico map costs US$37.