havent notice any fps loss my self BUT thats prob because i am testing just normal layouts not these super cab layouts lol.
i have also been compiling against the normal pinmame build not Destruks special cab build (he is gonna add my code once its complete)
the usb send command is all handled in separate thread so technically shouldn't effect the game play at all! but if people are seeing performance hits i can move all the usb code to another application you would run in the background and the pinmame.dll would just send it the frame data over a socket and the usb application would handle the board. but the fully integrated pinmame.dll should work fine.