For choosing addresses from Contacts, the software is the gold standard, succeeding at correctly identifying addresses where nearly all the other apps we tested failed. The program was even able to provide directions to a house on a rural road in Maine owned by friends that even the Maps app placed in the wrong location.
Like a few other apps we reviewed, Navigator requires a live cellular connection to plot a route, although the route is cached and can be used to a destination without a feed. Pulling up maps en route fails without a cell connection, however.
In 2009 we observed a rare problem in which AT&T Navigator would give very poor directions that offered illegal or dangerous turns. Fortunately, that problem didn’t recur in many miles of testing and along similar routes in late 2010.