I finally got around to testing out Ardupilot on a real flight. It was far too windy for a test flight and so was short and untidy. I'm now waiting for a calm day to get it tuned. I have an APM 2.5 installed in a HobbyKing Bixler 2.
There was some bad "porpoising" when I switched to auto. The pitch P value needs to be reduced though this is going to be time consuming with just myself at the field. The weather on Friday looks calmer so maybe I'll have another update soon.