Its been a while since i've flown the AJ, but from memory I set the CG exactly the same as what was recommended in the manual and it was perfect for 3D!
I only used a 2200mah thundepower though and it didnt need to be right up the front as papajeff's setup suggests!
Heres a clip with the setup i have had on it thus far.. Not sure if i had posted one already. but anyways...
http://au.youtube.com/watch?v=mHuKnMp5t8E