So I bought two glass screen protectors for mine and my girlfriend's iPhone 6s last week. Put the first on mine and it aligned and went on without a problem, but when I installed the other on her white 6 everything single edge had 3-4 millimetres than didn't adhere to the glass. These were mediadevil protectors and I emailed them about the issue and they have just replied telling me that the curved glass differs slightly on some iPhones as a result of them being made in a number of different factories. They said it wouldn't be worth sending out a replacement as it's likely to give the same results. I haven't heard this being spoken about before, so essentially what I'm asking is are they correct about the glass being more curved on some iPhones compared to others?