It's been a tough upgrade but with the newly balanced ailerons, stiffer center spar and greatly improved main and aft spar, this Zodiax 601XLB performed its second Phase I flight in great shape. It, as did I, gained a little weight in the process. Approximately 77 lbs! From an original W&B using small Nelson seats the weight was at 774 lbs. With the upgrade and heavier seats plus the wheel pants, the weight increased to 851. The new W&B is still OK for me but it cuts down on carrying passengers.