This is a general opinion based thread on the performance of OS X 10.8 ML on your Macbook Pro with a Core 2 Duo Processor. Understanding that many of Core 2 Duo users will be upgrading directly from SL, you can also compare ML with SL (I am upgrading from SL as well). Please talk about these things in your response: Overall, is ML snappier than SL or Lion? Are the animations smoother (such as changing desktops, notification centre, Mail, Safari tab view animation, including scrolling in ALL apps)? How's battery life with light usage or heavy usage compared to SL or Lion? Any little bugs or annoyance you've noticed (such as WiFi problems)? Did you clean install or just upgrade? Which Mac model are you using (I use MBP 13 2010)? Do you use HDD or a SDD? Any other thoughts? My motive to start this thread was so other older Macbook Pro owners can know if upgrading to ML would be optimal, especially knowing that older machines are likely to have more problems (as they did with Lion). I was one of those people who reverted back to SL after annoyances of Lion. Thanks your contributions.