So I received the replacement today ... and this one is worse!
Upon thoroughly checking the screen (using the YouTube "dead pixel text" video) it is apparent that there is a feint scratch in the actual LCD panel, going from bottom left corner to top right corner. About and inch and a half long ...
I KNEW I should have kept the last one! But then again, why should I have to "accept the odd defect" with a £699 phone?
I really don't want to get into the exchange game so I'm thinking of getting the next replacement then just selling it, without even opening the box. I am at that stage with Apple ... completely lost faith in their QC (with good reason).
Maybe now really is time for me to wipe my mouth and go elsewhere for my tech ...