Gps/compass location on frame

Hi, i was just wondering what is the ideal place to put the gps/compass on the frame. Is it best to install in (above) centre of gravity or it also works ok when installed on copter arm for example. Is there a way to adjust offsets like with dji naza? Would if affect the behaviour of copter if placed too far off center?

It can be placed anywhere on the copter away from motors and as long as it points forward, orientation does not have to be compensated.