I made a 4p panel for my cabinet. It was originally just a quick template to test out button/joystick placement and player positioning but I decided to keep it for a few months to figure out what I like and don't like about it. It will also give me time for feedback from other people.

The dimensions are 49" x 23" with a 4" rise from the front to back. Spacing between the main joysticks is 15 1/4".
No admin or coin/start buttons yet, I just have a keyboard sitting on top. Those are next on my list of things to add.
Some things I've learned:
- try to keep buttons far enough from the front edge so that the base of player's palms isn't on the edge of the panel
- my player 3 and 4 joysticks are 45 degree offset but when I've used them I found it un-intuitive. I'm going to rotate them to straight.