Here's a screen shot of some of the data that you get realtime with the Eagletree system. Right now the only problem is that you have to look at the screen while your flying. I have a friend call off the airspeed on the initial flights to find out where the stall speed is. I have low voltage alarms set for the battery and receiver voltage.

Pink - Altitude
Gray - Airspeed
Green - Receiver voltage - after the 6 volt regulator
Brown - Battery pack voltage