Usually when I have the Mail app full screen, scrolling on the right pane is very slow and sluggish. The left pane (messages list) scrolls fine. If I switch out of full-screen mode everything scrolls fine. Usually if I relaunch Mail it will scroll fine in full-screen mode at first but soon gets sluggish again. I never had this problem with Mavericks. I know my MacBook Pro is old (2010) but I don't see any scrolling issues anywhere else. Has anyone else experienced this?