It's apparent a gimbal guard will cause the 40-60' up and down yoyo effect, and new firmware will hopefully fix the 6-8' yoyo effect that almost everyone experiences with no gimbal guard, when suddenly stopping into a hover above 30'AGL. I think DJI is aware of both types of yoyo symptoms, which is a good thing.
So I just picked up my P4 from UPS and guess what..... they didn't repair it. They replaced the drone, it's got different serial number. I got a pristine new drone, stickers installed on top, not a scratch on the shell, no smudges on the camera glass, no marks on the rubber feet. I went all over this craft with a magnifying glass, it doesn't appear to be a rebuild,its flawless. So first impression is good. Tomorrow I'll take it out and give her a spin and see how she does. Tonight I'll do the IMU cal just to be safe and ground test camera, motors, gimbal, etc.
I originally sent it in with 3 complaints:
1. 40-60' yoyo effect (which I now know was caused by the gimbal guard I had installed). I explained it start out with a 6-8' yoyo effect since I bought it, than it grew to 40-60', and I provided DAT files to prove it. However, they told me to remove all accessories, including battery before I ship it to them.
2. 15mph top speed with OA enabled, it should do 22.
3. Poor signal integrity, losing control signal first spontaneously at 3000-4000ft distances (I've actually fixed that issue by using an Inspire controller), explaining to DJI my P3P goes 2miles under the same conditions and location where I fly all the time, and the P3P always loses video signal first.
Unfortunately they sent me the same RC back, same serial number. So I don't think they did anything to the RC to fix the control signal complaint. The strange thing is for the work done to the craft the paperwork stated "Phantom main control component - $96" with a discount of 100% since it's under warranty. But they sent me a whole new craft. Go figure.
I'll test the RC to see how it does, then revert to the Inspire RC again to compare.
I recently bought an Immersion RF meter just for grins. I plan to measure all the RF output levels between my 4 controllers and 3 birds. We'll see how they all compare.