I have just finished assembling my 450 copter and have done the ESC calibrations and all seems to work nicely. I mounted the props and took it outside for a test run. If I apply throttle the copter picks up in the front and wants to flip backwards. if I hold it and apply some throttle and apply forward, left/right, or yaw it does not change anything.
I have followed the order a seen in Youtube clips, loaded firmware, calibrated excell, callibrated comp and done the radio. when plugged into pc and I move sticks. it shows on the bars in radio call tab. motors spinning in right directions and in right order.