Tried your suggestions on my nervous phantom 4, I really thought you was onto something but unfortunately my drone still acts like a nervous horse.I finally had a chance to fly yesterday afternoon after updating everything last week. The updates went very smoothly for me. I updated the copter using Assistant 2, and I updated the remote using GO4 with my iPad Air 2 on WiFi. I then performed IMU, gimbal, and VPS (via Assistant 2) calibrations. I probably didn't need to re-link the remote and copter, but I did this as well.
Poking around in GO4, I noticed that my Sensitivity Setting had all changed as a result of doing this update, so I reset them as shown below:
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I set EXP of .30 for Gentle, Normal, and Sports modes.
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Of these three values, Brake Sensitivity is the one that could get you into trouble. I found 75 to be perfect and gentle seeming for the sake of the motors and airframe, but it is muted, and you have to be very careful and aware when approaching an obstacle like a tree branch which Obstacle Avoidance may not see. Once you get used to it though, it works quite well.
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As I understand it, the Gain settings dictate how the copter will react - on its own - to environmental factors (such as wind and air pressure variables primarily) in order to maintain its stability while flying. Having these set at their maximum or even default values may be one reason that some folks are seeing and hearing the autonomous twitching in flight after this update. I found 85% to be very smooth and steady across the board.
My flight yesterday went well. The wind was blowing fairly steady at approximately 10 kts at the surface and maybe 15-20 kts at 200' which is the highest that I went. I did not observe and/or hear the erratic behavior that some have mentioned. I did get frequent wind warnings on my iPad Air 2 - which I found very annoying - and I can see how this would be a bothersome issue using a smaller screen like an iPhone.
My first takeoff was from the lid of my carrying case, and the copter was at a slight (maybe 3 degree) angle. I noticed that my horizon was tilted the whole flight at about this same angle, and I was not able to adjust it with the C2 / Rt Scroll Wheel combo. It seems that this handy method of 'on the fly' horizon adjustment is now gone. I was also not able to adjust it via the Gimbal Roll adjuster in the GO4 app. The numbers did change as I attempted to do so, but there was no change in the copter's gimbal angle.
On the second flight, prior to taking off from the same location (and at the same angle), I performed a Gimbal Calibration. This time, the horizon was spot on, and all attempts that I made to make it tilt (360 yaws, flying sideways, and a combination of both) resulted in the horizon remaining spot on. I can only guess that this is due to the fact that I performed my post-update IMU calibration on a verified level surface, and the gimbal calibrated itself (in the field) to those values - regardless of the fact that the copter was sitting tilted at the time. This is something that I am very happy about, and it has been a long time coming.
I am also very happy about Tripod Mode. The speed of the copter in all directions is perfect for smooth filming of static or slow moving subjects, and I can see this as proving very useful.
As far as battery life, I saw no real difference. I did two 8-minute flights on one (standard) battery with the Gimbal Calibration between them, and I finished with 48% on the pack.
So, last thoughts. IMO, the greatest benefits of this update are a seemingly more level horizon and the addition of Tripod Mode. I also encourage those who are having issues to tweak your Sensitivity Settings a bit and see if things improve.
I hope it helps!
Wish I'd never upgraded, my drone used to fly perfectly and I had the utmost trust in it no matter what winds it was flying in.
It can't even fly properly in near perfect weather with little or no wind, very annoyed!
