[olddog]

Throttle response would better with Vacuum Advance. However the old vacuum advance physically has to move and vacuum has to drop with a fair amount of area to bleed off, so it cannot drop down to the mechanical advance only point, as quickly as needed like EFI can do. If you are driving along in a higher gear and stomp it, the engine will typically get about two pings in. In the lower gears, you would blow the tires off the wheels.