I had Bert Saunders make a plate for the Graflex Model D, which he sold to me, so that I can use the Graphic Graflex Back and Graphic Grafmatic 45 backs on both my Pacemaker Speed Graphic and the Graflex Model D.
I personally like the bag-mag. Twelve shots makes it a really cool tool. I also have an 1134 Grafmatic holder for the Graflex back, so I can have 18 shots in two holders. That's usually more than enough for me. (when using my Graflex Model B)
If you aren't part of the solution, you must be part of the precipitate.