FYI, on the CG change on the sukhoi.

To all who have or are considering getting the Hangar 9 SU-31 Sukhoi:

After receiving several calls saying the model comes out tail heavy, I
rechecked the CG and found that the location indicated in our manual is
incorrect. The correct cg location is 13/16" behind the CENTER of the wing
tube for precision flying, and approximately 1/2" to 3/4" behind that for
all 3D flying.
Balancing at these locations will make the model balance much easier and
should not require any nose weigh unless a very lightweight engine is used.
Balancing any farther forward than the above mentioned CG locations will
result in an is excessively nose heavy model.

Sorry for the confusion on this.