This is puzzling. I took some measurements from my Apollo and made some assumptions: 1) the recommended C/G is correct; 2) the only component location which can be varied is the battery; 3) the recommended equipment was used in the prototype shown in the photos. I have performed numerous computations varying weights of the tail servos, the motor, the battery(ies) (if 4S lipos are used), battery location from the one in the photo to maximum forward position. The worst case scenario, heavy tail - light nose, only required 6.5 ounces of nose lead (at the motor mount) to balance. Does the prototype have a lighter tail structure than the production version? I prefer a lighter model; so if I need to move the tail servos behind the wing tube I will. I also prefer to use a lighter motor for a 6S set-up. I certainly appreciate the information provided from those who have their Apollo models ready to fly.