From poking around at OS, baserunning has actually been made worse than it was in 12. Yikes.
Also, the speed ratings are lame. 99 should be Billy Hamilton level, 97 or so should be Yasiel Puig, and 95 should be Mike Trout/Peter Bourjos. Puig hit a ball to RF, paused with his hands in the air for nearly two seconds that wasn't horribly misplayed, and made it into 3rd base standing up by a mile. I live in southern California and get to watch Mike Trout on a near daily basis. There were multiple times on routine balls to the gaps that he easily made it to 3rd for a triple. He got an easy triple on a ball to the LF - LF! - corner, and the ball wasn't misplayed at all.
In short, if your player has 99 speed and baserunning ability, nearly every ball in the gap that reaches the wall should be a triple. Not a contested double.