sentences:  In 2008, after being used for 20 years, the Rebound Ace was replaced by a cushioned, medium-paced, acrylic surface known as Plexicushion Prestige.Roger Federer and Serena Williams are the only players to win the Australian Open on both Rebound Ace and Plexicushion Prestige.The main benefits of the new surface are better consistency and less retention of heat because of a thinner top layer.