I had the Alware 3-Axis 450/500X pro mounted on my GAUI 500X ....that thing rattles and shakes like my grandma....landing skids break very easily....no smooth movement possible.
http://www.alwarerc.com/shop/eagle-f450550-pro-v3-camera-mount-p-57.html
I changed to the GAUI Crane III and I am a happy man now...high quality stuff, no rattling, very rigid......TOP product
http://helidaily.com/gaui-new-crane-gimbals-2-3-information-released/
Chris