I did some extensive flight time last weekend with my P3A using the v1.2.8 firmware and I had no issues as far as the firmware goes. I flew half the time with a ipad 2 mini and the other half the time with a Nvidia Shield tablet. I never calibrated the IMU after the upgrade in firmware, but I did multiple calibrations for the compass and GPS during my 2 days of continuous flying. I will say that I found the iOS version of the DJI Pilot app to be MUCH more stable than the Android version. I ended up returning the NVidia Shield to get my money back after the trip.