I just finished building the CG Cub for a friend not too long ago. Due to the fact he owned a nice OS .91FS and it is also being used as a float plane I added in even more reinforcement to places like the fire wall and LG block. It's really built like a tank, very strong wing. The wings on the GP Cub, not so much. My own GP Cub I used an OS .70FS and it was a bit over powered for the wing. It tended to flex a lot at full throttle. The CG was more scale then the GP but as stated by TG, it isn't real scale either, just a bit more so.
The fellow I built it for also bought the fiberglass cowl and one piece LG from Fiberglass Specialties. That was a nice touch. I installed a pull/pull rudder and used two servos for both the elevators and ailerons. It was CGed center as to the plans and required zero trim on maiden.
My hope is to see some photos of the finished SIG in this thread too. I think I only have one photo of the owner and plane I just built for him. He covered it and used Solartex Cub Yellow. We are both happy with his new plane.