I enjoy Mountain Lion for what it is - a Beta release. Unfortunately, I've been having some issues with my MacBook Air 2010. 1) Does everything lag for you? Everything, from scrolling in Safari to switching tabs (in Safari) to switching between Dashboard and Desktop lags. Unbearably. I hope this isn't the way Mountain Lion is going to be released. 2) Does Software Update work for you? I've been trying to get iWork updated, but it always hangs at 99% downloaded and then pukes up an error 102. I've had to update the entire software suite manually. 3) Do some widgets keep moving around when the Dashboard is refreshed? The one widget that seems to do this with regularity is Weather. It ALWAYS moves down - in every single release of Mac OS X, the Weather widget always moves down.