Can someone, in detail, explain to me what the lag issues are on the rMBP? Where they occur, and if it can be fixed via hardware or not? I know there's a scroll-lag, but I don't know much about it. What browsers? Under 2880x1800 only or 1920 as well? I've heard about Mission Control lag as well, any info about this? Thanks EDIT: It seems scrolling lag is only apparent in certain resolutions/scaling options? Which ones? EDIT2: My current computer lags with an actively changing desktop (every 10 seconds) and swiping back and forth on launchpad while the background changes. Can anybody see if there is any studdering whatsoever on the rMBP (on different scaling options, too, if posisble). Thanks EDIT3: Can anybody see if lagging is still apparent (on ML) while a youtube video is running? It lags on legacy MBPs but not that much (about as much as a rMBP lags normally from the video(s) I've seen). Does ML fix this AND give a performance boost to boot? Or will scrolling through youtube comments forever be studdery?