I took both out for a flight today - same winds, same location.
I can't help but notice that the Phantom was more "obedient" - it doesn't YAW and move by itself so much. As for the INSPIRE - I noticed there will be times the camera, and/or the craft would YAW by itself.
I use "Follow Mode" for the gimbal... I do compass calibration....
The function is hidden in ADVANCED SETTINGS, with the warning "Only Advanced users should modify these settings. Make changes with EXTREME CAUTION." I don't consider myself an advanced user, and none of the manuals mentioned anything about IMU.
I hope this solves the problem. Strange thing is after calibration... after a while I check again it says I need to calibrate again - all these while with my craft lying still on my bedroom floor......
Hmmm... is there anyway to do an advance calibration in South East Asia? Our weather temperatures are consistently 30 degrees celsius, and every time I want to do an advance calibration the APP reports over heating?
DJI stated today that there is a known IMU bug causing crashes on auto takeoff. Apparently it causes the yaw issue too that I have seen myself. A firmware is coming to fix. In the meantime, they say to perform an advanced IMU calibration to be safe. (Their post is on rcgroups if you want to see it. )