Bigfish,

I have the GP Extra 300S ARF and installed an OS .46 FX in mine too. It is a great flying plane, you will love it. If you have RealFlght G2, it flies very much like the simulator model (I think add-on pack 1)

The manual and assembly instructions are great. The only things I remember having problems with were:

1. Installing the tail landing gear wire per the instructions interfered with the lowest pre-cut hinge slot on the rudder.

2. The manual did not tell you to install the wing bolt-on reinforcement plate.

Other than that it was straight forward.

Best of luck.

Carl