I have just tested the GPS a couple of times but I have also not observed extremely bad performance with regard to getting a fix. Maybe not as good as my BT-338 but OK.

I have not managed to figure out how you should use the buttons on the front. You can select and application to switch to but it seems you have to press the screen to activate it so why do you not use the the screen to select it also? And what is the use of the other button? And what is the thing in the mddle of the button?