Hi
Below is a photo of my Picade mod
I used a 12v DC 5A power supply (just in case I want to later change the screen for a 12.1" in the future). This is fed to the ATXRasPi through a car 12v to 5v converter capable of supplying 3A. The ATXRasPi is used to control the power to the Pi from a push switch on the side of the cabinet. The homemade PCB on the right hand end of the Pi GPIO enables a script called from the menu to activate the ATXRasPi in the same way as pressing the switch.
The Picade can then either be shutdown / rebooted from this switch or from the emulation station menu.
I replaced the supplied audio cable with a shielded one and the sound is perfect unless you turn it up to over 22 (i currently have it set at 15) then there is some slight white noise.
Cheers
Paul