All my returns were due to screen issue. eg dead pixels and light bleed.
I still thinking Apple need to scrap LCD screens because I had seen three of my work colleague Note 4 screen none of these phone's showing any light bleed or dead pixels the quicker Apple move to AMOLED means less returns.
I've seen dozens of iPhones without any screen issues, so what?
Actually the worst device I have in my home about light bleeding are my son's Galaxy S4 and my Nexus 7.
And I'm very happy about Apple use of true RGB matrix display and not those PenTile panels......