After dealing with the motor issues (0.5-1 degree off alignment on 3 motors), the hexa is now performing really well.
Here you can first see a little stabilize test. Excellent performance, quick compensation. There was 'some' wind here, about 2-3Bft.
Then the first fully autopilot flight @ 60m high. Amazingly, the hexa just goes straight up as if there's no wind whatsoever. See the flight log in the end. Only one leg was deviated slightly probably due to some temporary wind gust. In this test I'm already using the 143g camera payload and the large battery. Current consumption was 15-19A during flight in wind. This makes it reasonably comparable to the hover test. After two flights, the stab test and some 10 mins on the ground for preparation I had 15.8V left in the battery without load.
This build is with the RCtimer motors and the slim props. So the concept as-is works, but I'm awaiting my new hobbyking motors @ 530kV which I intend to test with my 14x8 graupner props instead. This will probably draw a bit more current, taking away some endurance, but the hexa should have more thrust available that way.
Conclusion: Very happy. With the autopilot this machine works like a charm, but available thrust remains an issue of concern. I'm using a very gentle 1 m/s descent/ascent speed and 5 m/s forward speed.