went to a central london apple store for my appointment. I had the laptop on with a window open ready to show the Apple Tech the issue.
He came up to me as i was sat on a bench finishing a time machine backup in case they were ready for me then and there.. asked me what the problem was, and I always think it's best to act stupid even if
youre a pro expert like me about part numbers and IOGREP and LG vs Samsung.
My approach was.. love this computer! Apple is so great! In Gods image! Yet, look at this strange effect happening?

How can this be because apple is the best?
He took one look at the grey background and the image retention effect and said yep. I dont have any parts now but I will order one for you, call you when it is here, and we will give you next day or possibly same day service if you can come in the morning :O i didnt even have to go to war as i was prepared for.
As he was going through his booking process for the repair I asked him if hes had a few of these before. He said yes tons. Apple even made a new category of image retention on their service system specifically for the retina display (they didnt have this category before the 15inch RMBP).
He said that its the easiest service repair at least and they've ironed out the issue on all new pcs
Cant fault apple for their service though. Really great service, at least here in London.