I have a a rMBP and it's absolutely gorgeous and it came with an LG screen. I thought I did not have any image retention on my display but I learned in another forum how to accurately test if my screen displays an image retention issue. So, following these somewhat extreme instructions I was able to finally see the issue. This test opened my eyes to the issue! Now I am curious if others with either Samsung or LG who previously did not see any image retention issue if you see one running this test. 1. Run the command in a terminal window to see if you have LG or Samsung: ioreg -lw0 | grep \"EDID\" | sed "/[^<]*</s///" | xxd -p -r | strings -6 2. Set your desktop background to the darkest of the 3 solid gray backgrounds that come with OS X. Then, open up a picture of a black and white checkerboard with preview and blow it up until it fills the screen. 3. After about 15 minutes, minimize the checkerboard image and uncover your screen. 4. Report your results.