Every post I've read said the scroll lag has cleared up with Mountain Lion. My rMBP is fresh out of the box, so there shouldn't be junk temp files or caches kicking around. Textbox lag: For instance, typing in this message text box to submit this post is laggy. The letters shown are lagging what I have type by maybe a 1/2 to 1 second. Scroll lag: This page is very laggy: http://www.redfin.com/CA/San-Franci...email&utm_campaign=instant24_listings_update# This is all on battery, with default power options. I have to say, I'm not very pleased after spending $3000.