I've had the Racelogic Performance Box for a while now and I've used it at a few events.
I've been pretty happy with it but it works much better with an external antenna. The unit itself is pretty well designed but the buttons are a bit small to use with gloves on, the screen is a bit cheap looking and the interface is pretty poorly designed.
That said, it works very well and produces good output, particularly in being able to show cornering lines and braking markers.
pyspeed1
Performance Box is Cool 
