I am building one myself right now.

One thing I noticed different from my last Aeroworks 60/90 is the DISTRIBUTION of weight and complete lack of engine thrust in the firewall.

WEIGHT
The fuselage is extremely light.
The elevator and rudder are pretty heavy.
Fuel tank is mounted up tight to the engine.
The battery is mounted up close to the engine.
If you mount three servos in the tail as instructed, you will likely be putting all gear and weight toward the nose to compensate.

All this adds up to a pitch sensitive plane, because the moments of inertia are so far from the center of gravity (fulcrum) of the plane. Its easier to control a teeter-toter with 600 lbs in the middle, than with 300lbs on each end. The correct distribution of weight is important as well as how much, and balance point.

THRUST
No thrust angles are built into the firewall. YOU MUST ADD THEM or suffer an un-trim-able plane that reacts to inputs differently at all vectors and throttle settings.

Personally, I will attempt to keep light servos on the elevator, but mounted as far forward as possible. Rudder will be pull-pull from the center of the fuselage. Fuel tank will be mounted as far rearward as possible allowing for stable idle and operation.

I remember the Aeroworks was pitch sensitive too, just go VERY easy on the throw rates. A little dab-l-do ya.

Oh and by the way, are you balancing the plane UPSIDE DOWN or right side up? Wichever way lets the plane sit tilted, but not tipped over when its out of balance is the one to use. Low wing planes balance upside down, top wing balance right side up. Mid wing (edge 540) will tend to be one or the other.

See ya !