The wing installation is so easy I don't know why you'd want to put it anywhere else. I retrofitted it there in my -8 in a couple of hours.
Is there some perceived advantage to having it in the cockpit? The only advantage I can think of is not having the long run of wires but it really wasn't bad. I pulled a wingtip, fed the tubing down through the holes in the ribs, pulled the root fairing and ran the wires.