I got them last month, download to USB and just upload. I had an issue to start with but, just reinstalled. The alerts give you speeds on A road and Motorways. The speed symbol comes up when you have the nav screen on to the left hand side. Once set correctly, the cameras come on with a shallow beep and the touch screen displays the type of camera and speed. This over rides what ever is on the screen at the time.
I've used them around Hampshire with next to no errors and on a run to Leicestershire it was spot on.