This was player driven, not pushed by the Tour.
Rory spoke about it today at his press conference. He expects it will significantly slow practice rounds but speed up actual play.
This is different from rangefinders. All pros can walk off yardage to a close enough distance and they dramatically speed up play.
Not everyone can read greens as accurately. It is a skill that you don't need and yields no advantage with book.
The Masters doesn't and never has allowed them. 😉
