Tukkus, there are three primary changes I made to the design, a couple based on customer feedback, and a couple I just wanted to do....

The first change was to add a small ply doubler to the fuse where the landing gear mounts. While I never broke a gear mount on any of the 4 version-1 protos I built, several customers did. The new design is stronger. While I was redesigning the doublers, I redid the engine mount. The previous mount was solid 3/8" ply with lightening holes. The new mount only has ply where it needs it for strength, and the rest is balsa. That design change alone cut 1.75 ozs from the weight of the finished bird.

The next change I made was to redesign the alignment of the wings. I changed the stagger significantly to improve inverted harrier performance. The wing saddle and interplane struts were redesigned to make this happen.

The final change was to try building the bird with the aileron servos in the top wing. This moved the vertical CG higher on the airframe, and improved the inverted harrier performance a little more yet. The new kit can be built with the aileron servos in either the top or bottom wing.

So the new kit weighs a couple ounces less, and has better inverted harrier performance.