After only a few perfect flights today this unit would fail to perform proper compass calibration. First rotation would result in green light, second axis rotation would result in steady yellow light then go to green slow flashing. Even though the flight control lights would flash slow green and confirm GPS mode, it would still not fly a straight line and would yaw left or right without input from controller. Luckily I got her close enough to me on all 3 occasions to catch her by the skids and kill rotors. Crash avoided. I completed basic IMU calibration and advanced IMU calibration 3 times and my values where always between 1400-1500. Never seen anything like this in my life. Called Dronefly.com and they advised to ship back and they would replace unit if it was defective or refund my money if I chose. They were told not to send this unit back no matter how it performed for them. To many times have I taken vehicles to the mechanic with a complaint and once they test drive it, it would function without fail only to leave me on the side of the road days or weeks later. I requested a complete replacement or refund. If I would have taken this bird to altitude there is no doubt there would have been a flyoff that would have resulted in a crash and loss of $1,400.00. Folks, pay attention to those flight control lights and make sure she will hold hover within a 3-5' radius. If she rolls or yaws in either direction get her down as fast as possible and get under her. There is no doubt I had one of the fly away V2+. So, far Dronefly.com has been wonderful even though I was kind of an ***. I did call back and apologize to them personally as its not their fault, they didn't build the unit. So far nothing but good things to say about Dronefly.com. (Just received FedEx call tag, they even paying for shipping back to them!) I am sick because I am now without my V2+, I admit it I am now addicted to this aircraft.