I have two MacBook Pros, one Late 2008 (model 5,1) and one Early 2011. I use the Early 2011 MBP primarily. I decided to install OS X 10.8 on the Late 2008 MBP first, to test it out. The result was not promising. The Late 2008 MBP used to have OS X 10.6 on it, and the upgrade to 10.8 made it considerably slower. Everything is slow. Even starting System Preferences, with no applications running, takes like 5 seconds. My Early 2011 MBP has OS X 10.7 on it (which the Late 2008 never had), and at this rate I am afraid to upgrade it to 10.8. Do you think 10.8 will cooperate better on my Early 2011 MBP, because it is more recent hardware? Did anyone else find that 10.8 made their Mac much slower? Is there anything you found that helped? Thanks.