There have been reports of burn in on AMOLED displays due to a glitch that disables burn in protection. I presume they are working 24/7 to fix this currently because it could send in thousands of devices for repairs and that is definitely something they don’t want. I have been using 6.0 for a few days now and it is fine. Just make sure to avoid static images if possible, particularly your taskbar. Make sure to switch to full screen frequently so the status bar doesn’t stay lit for hours with battery/wifi etc indications because this will cause the burn in.