The European Tour played a tournament with a shot clock in June.Kevin Na took a lot of flack for being slow, but I never thought he was that bad. At least he is not bad now. Frankly, I think many of the younger players play slower than he ever did. Patrick Cantlay is brutal to watch when it takes him a minute standing over the ball before he swings. Speith is brutal as well. Think the tour needs to get tougher on these guys when it comes to slow play and start penalizing more to make them play faster. It is an absolutely a joke that a group of 2-3 professionals take over 5-6 hours to play a round when an amateur group of 4 mid to high handicappers can get done in the same amount of time.
https://www.golf.com/tour-news/2018/06/08/european-tours-shot-clock-masters-debuts-rave-reviews