Finally real success! I got back out there this week with a fully waterproofed servo, an added lidar sensor and a major code overhaul based on Test Flight 1's test data. Observations were:
1) Pitch control is now much better. While I still think the control loops could be better tuned, I am now getting long runs with very good pitch stability and no more porposing as you get with the wand-based systems. In lighter air, I suspect that the lack of paddle / wand drag will allow me to fly more easily as well.
2) Servo waterproofing worked great. 20 knots of wind and lots of spray and crashes and the servo never blinked. This was a big victory and only involved some grease and spray urethane.
3) There is still some servo chatter / oscillation. It is minor and doesn't affect performance much but it is bothering and inefficient. I will comb through the data and see what code changes could be made to maintain the low latency reaction while smoothing the servo reaction.
Two and a half hours of good foiling and 5.5MB of data taken. Great day out there and lots more data to pick through! In another few flights it might be time to think about the follow on to this prototype. Lighter, smaller, sleeker and more awesome!