First off the CG Extra 300 is one of the nicest and well behaved flying sport models bar non that I have flown, and to the best of my knowledge it was never supplied with a foam wing, but had built up one piece wing that was quite light. Rather than start answering your questions here and repeating myself do a search in this forum for "Goldberg Extra 300", as there is a lenghty thread on the CG Extra 300 which answers all of your questions and then some. CG Extra's have been known to weigh in excess of 11 lbs. and still fly great, as mine at 10 lbs flat with a G23 gas engine is simply a dream to fly.

Karol