I was extremely disappointed on launch day to get my $1300 phone out of the box and lay it next to my old 6+ only to see right away that it had dark corners and the blemish shadow. The display was visibly inferior to the older phone and it was a big let down after all of the hype.
Apple must know the displays are not as good on the new phones, but they sent them out anyways. I feel a bit cheated by this, especially at the silly prices the phones go for. I don't think it's all OCD on my part, but rather there is a bit of consumer anger involved as well.
The picture I posted is of my second phone which was the best screen we had seen here on a 6S+, but it still had darker corners and the pinched glass blemish. The picture doesn't really do it justice to what you see in the hand or at any angle.
Anyways I ended up getting a phone I can live with now, and it is so much better than the first two I feel the effort was worth it and would recommend that anyone who is unhappy do the same and clearly tell Apple why.
How many replacements did you get? From what I recall, you're on your 2nd replacement?