I spent the morning checking this out, the d pad doesn't have any lag on a short test cap for the digital pad, so I guess it's my sucky code...although I have found that the pad and joystick controllers can sometimes have a dead zone in the center which can be received as lag.. I tried a digital 360 arcade stick so I coud hear a solid click as feedback for the joystick responding, also monitors can be slow to update...
Hmmm...
Apologies for wasting anyone's time