As I mentioned, I choose to wear my/Marvin's pack on the front of me. This way he is facing the direction of movement as if he were moving under his own steam, I can see what he's seeing, I can see if he needs better shade, nobody can sneak up on him without my knowing, and I can't forget he's there. People's regard for personal space prevents most from getting too close to him because it would mean getting too close to the front of ME. Not advisable.
Marvin continues to love his pack and I can now say I would definitely recommend them to all who are curious. The only downside is that if your particular bird doesn't like it, you've just spent a wad of cash that may be hard to get back!