ArduCopterMega, the next version of the official ArduCopter code, is flying well and will bring full UAV navigation to ArduPilot by syncing it up with the APM codebase. Right now Jason Short is testing it on different airframes. The video above is it running on a stock Gaui 330s frame, with default settings. Late in the video Jason tries some different PID gains, but you'll see there's a bit of oscillation and they're not as good as the default. Awesome to see that the code can handle quads of such different size (the Gaui 330 is about 60% the size of ArduCopter) with the same standard settings.