I had a bit of trouble using the Pharos to navigate the rather crowded streets of New York City. For example, when I tried to program in an East Fourth St. destination in Manhattan from a starting point in Brooklyn, Ostia kept locating my destination in Brooklyn. (Yes, there is an East Fourth St. in Brooklyn, but I did specify New York, NY.) It wasn't until I entered the zip code that the existence of the Manhattan street was accepted.
The software worked better once I got into the wilds of Long Island. You get two types of audio feedback from the Pharos: A female voice, which lets you know about upcoming turns, exits, and the like; and a "ping" that lets you know that it's now time to make that turn. I had no problem understanding the directions given; the speaker is a bit tinny, but that's not unexpected for a device of this size.
The directions were good and the combination of the voice warnings ("Right turn ahead") and pings seemed to work fairly well for simpler highway and street driving. I did find that some of the warnings for upcoming exits were a bit premature, and occasionally a bit late (one coming after I had already gone several yards onto the exit itself). In addition, since the voice doesn't specify highway numbers or street names, things can get really confusing if you're being told that you've got an exit coming up, and there's more than one highway exit to choose from.
As a result, while the GPS could be really handy if you're lost in an unfamiliar area, I'm not sure I'd use it as a day-to-day tool. At the very least, I would check the text directions carefully before setting out. Since the voice directions aren't that informative, and presumably you won't be checking the screen while in motion, you're better off using the GPS when the car isn't moving.
The Pharos Traveler GPS 525 is a sweet little device, and if you like the security of having a GPS along with you so that you can find out where you are, and where you're going -- together with a well-designed PDA -- it's worth the $500 or so. However, don't expect it to be quite up to par with some of the larger, dedicated automobile units.
Pharos Traveler GPS 525
Summary: This is an elegant combination of PDA and GPS; however, the GPS software can be quirky.