New 15" rMBP (fully maxed on specs). Just installed CS6 and was playing with Photoshop. On a simple file (4MB jpg), I'm finding that simple things, like brightness/contrast adjustments, are sluggish to display. In other words, if I grab the slider for brightness and drag it, either slow or fast, the updates in response are chunky, not showing a smooth gradation. What's up? This machine should be able to kill on PS. I tried some different settings in the Performance settings of PS, but don't see any difference. I started on 1680x1050 but then tried it at the 'best' setting with the same results. My 2010 MBP was more responsive than this is. I'm fully updated on CS6, but do I have to upgrade to the cloud version to get decent performance? Any other tips?