If you are talking about mounting the 3GX, I mounted it to secure and conceal the wires better. Also, it puts the gyro right under the main shaft, which is the rotation point helping control the tail just a bit better. I just never liked the gyro mounted up top. Looks ugly to have all of the wires up there. But, if you want to mount it up there, you can. It's your heli, make it your own.