i think he's talking about the I/S/Z rotations. with SRS if you rotate I or Z left, or S right, the piece shifts towards the direction of rotation, unlike with ARS. this can save keystrokes and allow a player who's nearing their physical limitations to place more pieces in less time.
Yeah the following features make SRS faster in those modes. 1) no ARE 2) locking hard drop 3) the 4-state rotation.
