Sounds awesome. At first, I didn't really care for a "feature" like this. But now I'm getting sick of plugging and unplugging. What happens is that I end up making gaming choices based on how the cabinet is currently set up.
Same here, this was not a consideration when I first built the cabinet. Then I installed a DC with hacked pads but soon got fed up of unplugging/plugging molex connectors. This system I now use meant I had to re-wire almost the whole cabinet, but it is much neater and more functional for it.
Is your switch knob externally mounted?
I have the switch just inside the coin door, along with volume control, monitor controls and USB2 hub. Oh, and also access to the Dreamcast. I've got a little USB light permanently plugged in to the hub so it is easy to see what you're doing.
I did think about mounting the switch on the top of my cabinet near the power button, but it was too much effort. Opening the coin door isn't a big deal. Now I just have to get on and finish my zero-cable swappable control panel idea...