Do you have your speakers on? I ask because when you activate the voice over utility with command + F5 (which I was always doing when I switched) t can make the system pause while it speaks to you.
[.edit] whoops didn't see you'd worked it out already
[.edit] whoops didn't see you'd worked it out already
While tweaking unrelated System Preferences I came across a setting "Put hard disk to sleep when possible"... turning this off (ie disabling the checkbox) has resulted in significantly fewer pauses using the system... I think the Mac was aggressively sleeping the disk...
As of right now I'm a much happier camper wrt my MBP performance.
Cliff.