MAC was calculated per the website I issued in the Kfactor (if you need it, I'll send it to you via e-mail). It is not 25% of the wing root. There was no problem at 25% but the plane felt more "comfortable" to me at 27-28% for the spins and snaps. As Mr. Kimbro said, there is a lot of truth to the CG being a matter of personal preference with today's 2M ships. We discussed this many times you and I at contests and even back then, we were playing with different %'s. I got all the way to 25% and Iwas able to start removing some of the mix. What Ifound was that I personally flew the plane better with the CG just slightly aft of that. I wound up just a tick over .5+ per Hebert after discussing with him but wound up going back to 0 when I went to 28% MAC. You may just need a little more positive incidence with the contra. I also think that with that adjustment, you'll see less mixing as well. I think the slower the DJV flies, the more + incidence you will need to carry. Ionly say this due to trying all sorts of props from the 20x15 all the way through 22x12 which obviously varied the flight speed envelope drastically. The slower it flew, the more it seemed to need as witnessed by Bryan Hebert. I spent 4 days with him and this is what Ilearned.