Autostrategy has little to do with whether a PX drive will reach 16x. If the firmware detects the disc will burn at up to 16x, turning off PoweRec will allow it to burn to 16x. Autostrategy only determines if the drive will derive the write strategy parameters from the disc or from firmware. If PoweRec is on and the drive makes a proper write strategy for the media, any media defects such as tracking, focus, eccentricity, whatever, would still cause PR to kick in and drop the speed. Autostrategy on/off/forced is only for the 755/760.