Before anyone tells me otherwise, let me make it clear that there I am not interested in hearing that there is no scrolling lag. I have seen videos confirming its presence (in Lion) and even Anand's recent review has talked about it. What I want to know is, under what circumstances does scrolling lag occur? I heard that in 1680 or 1920 mode, everything is rendered at double the resolution and scaled down, so is scrolling lag only present under these resolutions? (seems plausible to me since most people prefer these modes) Is there any lag in 1440x900 mode? (non-retina) Any on 2880x1800? ("Best for Retina" mode) Thanks.