Randy Pobst a 5 time SCCA National AutoX champ AND a ALMS Porsche driver would beg to differ.
He double-clutch downshifts even with syncros... NOW he doesn't downshift all gears.. he gets thru the brake zone, slows down and then double clutches and picks the proper gear for the corner exit.
It isn't a hard thing to learn and isn't a bad skill to have.
BTW it will save the syncros if done properly.
