OK, I've been reading the lag complaints on this forum over the last few weeks, and never really experienced any lag that was enough to bug me in the least... until today. The irony? It was a positive review of Mountain Lion linked to on Apples own website... Safari's default home page. Open this link in Safari, scroll up and down: http://techcrunch.com/2012/07/25/os-x-mountain-lion-review/ Ok, a little rough? Now pinch zoom the page a bit, and try it. It just about freezes. Now look at Safari's cpu usage. 70 - 80 percent just sitting on the page! I tried the page in chrome beta, works just fine.