Hi Elliodm,
My setup is the following, the CG of the 6S Battery is next to the wing tube, as the manual state, no issues here with the CG... I have been flying a 3DHS Edge 58", so this YAK 55 is less crazy but FUUUUNNN to fly. Personally when I like to fly Crazy Abuse 3D I choose the Edge, when I like more calm 3D I use the YAK, still the YAK can hold good level of abuse but I like the way soft fly, soft Rolling Harriers and other soft tricks... you wont regret this plane:
Motor: Motrofly 4315-480kv (no spacers needed)
ESC: CASTLE CREATIONS CREATION EDGE 100 LITE
BEC: CASTLE CREATIONS CREATION CC BEC PRO 20 AMP12S
Battery: GensAce 6S 2700 mah 25c
Servos: Hitec HS-5245MG all around
Prop: Xoar 15x8 PJN Electric Series Beechwood Propeller
Spinner: Great Planes Spinner 2-1/2" Nylon White
Extras: Dubro Arms, Servo Extensions and safe Locks.
Have fun with it