Well I maidened my Katana last weekend and i can't understand why this thread isn't on fire. I can't say anything about the build as I didn't do it but so far this is an amazing fluing plane. With a YS140 and two 2100nimh receiver batteries I came in at 10lbs 3 oz. My cg without fuel is right at 6inches behind the leading edge and my tank is just in front of the wing tube which may be moving it forward some. It seemed like I could move it back a good bit for better 3d. Does anyone with experience with this plane have any thoughts? Also my wing is all the way back so I can move it forward or move batteries back which is the better solution? Is there an optimum wing position that anyone has found?