I just bought this, downloaded it (very slow) and have been playing with it in my office. I love it. There are some things that could be improved, but this is close to exactly what I was looking for in a navigation app.
Reading this thread is very strange because we have two opposite extremes of argument against this... sometimes coming from the same people. You can't argue that the Google Maps app is just as good as this, AND argue that this is unsafe to use because it doesn't have voice prompting. Its totally illogical.
I have been using PDAPhones since they were first available and have used nearly every major navigation program available on them, as well as having used stand alone GPS devices. Other than audio, this one seems to be pretty good. Personally, I don't see what the big deal is with audio prompting. I rarely turn it on, and when I do is more for a reminder to look at the GPS device when I'm on a long trip with long periods of time between turns. Otherwise, the device tells you how far it is before the next turn and you can just give a quick glance periodically to double check how close you are. Anyone that thinks that this is unsafe is not being reasonable. How is that any different from glancing at your speedometer or rear-view mirror. Its part of driving. Actually, how is it any different from glancing at a street sign to see where you are. Voice prompting is not a big deal.
I have used the Google Maps application extensively for navigation, and IT is very dangerous. It gives you turn by turn directions, however you must keep track of where you are and index it to the next turn for each step. After indexing to the next turn, you have to turn back on the active tracking. This is two manual steps needed at each turn... often several times per turn when the ramp is considered a segment. God help you if you get off track and have to re-route yourself... you basically have to redo your route and retype in "current location" as your starting point. Comparing that scenario to G-Map is ridiculous. G-Map gives you turn by turn directions without you touching anything along the way, and re-routes you if you get off track... like any GPS device does. The lack of audio prompting is a minor issue and is a nit compared to the other differences (especially safety) vs. using Google.
