sweetLemonade

The only thing which affected input lag in APB are the OneThreadFrameLag and the mouse fix. What you experienced is probably less tearing, thus perceiving it as smoother. You could try FastSync or the AMD alternative of it in the drivers (cant remember the name of the amd equivalent), or just cap the game at a framerate you enjoy with rivatuner statistics (part of msi afterburner as mentioned in this thread already)