I have an interesting bit to add to this dilemma.
So I have a DNP serial number iPhone 6, silver in 128GB. I have what to me seems an obvious backlight bleed around the status bar and specifically surrounding my battery percentage indicator. The bleed is a shade of grey, most noticeable on a white background, for example when I open safari on a blank page in landscape. If I turn down the brightness, it is much more obvious.
Yesterday I went to the apple store and two genius bar employees examined my phone and both stated they could not see the problem and what I was talking about. I knew that I wasn't crazy so I researched and low and behold, I found this thread. I printed all of it and returned to the apple store today, showing that this is becoming a more and more reported issue.
Today my genius bar employee examines the phone, acknowledges that he also sees the problem and takes the phone "to the back so a senior technician can examine it."
Within a few moments he returns and tells me that this is NOT a display issue but in fact an iOS8 software issue which is "known to apple" and will be addressed in a future software update.
Anyone else have a similar experience?