infinity-it:
The device can be placed pretty much anywhere in the aircraft. Goes on with a velcro patch on the back. We initially used the GAU-1000 with the integral antennae, but have decided to purchase the GAU-1000A with the GPS antennae on a 5m lead.
Data update rate is 4Hz, using WAAS, so if you don't have WAAS, it might not be as good.
I have noticed the vertical channel is a bit less accurate than the horizontal position, but that's to be expected.