RE: Great Planes Spirit 2m glider
I have a Spirit 2M. It was an easy build following the instructions. My experience has been that the fuselage is probably overbuilt. If I were building it again, I'd add some lightening holes.
The recommended balance point is on the wing spar, but it can be pushed much further back. I'm flying it with the CG at almost 50 percent of the wing wing chord at the root. This condition also allows you to not add additional nose weight.
I've since electrified mine with a 35-30-950 Rimfire motor, a 35 amp silver series ESC, a 1250 mAh 11.1 V LiPo pack, and a 10x6 folding prop. All up weight in this condition is 39 oz. It will easily climb in excess of 500 feet in about 30 seconds, and I can get 6-8 climbouts on a single charge. Without the motor, the plane flys well off a high start. I just got tired of walking all over the field.
I have specked it out thermaling on a good day, and had other days when I couldn't buy thermals. This was not my first plane, but it is my first sailplane. Watch out for the tip stall, but its quite manageable.
Brad