Well, I had a fairly disastrous maiden today with my Skybuggy 300. Balanced on the main spar, near the rear of the recommended CG range, the plane was uncontrollable. On take-off, it went straight up…
I jammed the battery all the way forward and the plane went from unflyable to merely extremely twitchy. (Yes, I flew it with a bent shaft and grindy bearings, but not for long.)