I have it and for the most part I like it, I just wish it had a tutorial on how to use it to its full potential. Also I don't like that you can see where you would like to go on the map but unable to just touch the screen and add that spot as a waypoint. I like thT with it on the phone you basically have your phone and a GPS thus eliminating one more thing to have to take with ya.
Short answer is yes I think it's worth it especially if you are familiar with GPS as I think you can do more things with it than I can figure out.
OBH