rjtetc,
I have found the Dual unit very good, but have not used it enough yet to determine the real battery life, except to say that the it is longer than the endurance of any aircraft I might be flying that doesn't have a brasco.
The Bluetooth pairing with the iPad2 was simple, the time from on to providing GPS information to the iPad is much faster than some of the TSO GPS I use from time to time.
Indeed, I can get a useable GPS output sitting at my desk at home, something neither of my TomTom car units will achieve, my TSO Trimble/Freeflights are not in the hunt, despite clear line of sight reception to an external pre-amp equipped antenna.
Tootle pip!!