So I went to the Apple store and was able to have my 32gb Gold 5S retail-exchanged at the Genius Bar as a result of the scan lines issue.
Unfortunately, my replacement also has this problem. It's slightly less noticeable, so I'm just going to deal with it.
With that background image, the only time I see the flickering at all is when I hold-to-save. The shaded area that is generated above the "Save Image" button flickers significantly. I can see the flickering at not other time whatsoever. I can't even see it if I set it as my background and adjust the brightness so that the image is as dark as the shaded area in the save image dialog screen. That boggles my mind a little bit. Is it possible that the flickering I'm seeing is just a product of the GUI effects generator, and possibly something that could be addressed down the road with an iOS update?
Also, is there any chance at all that it's simply something that needs time to "break-in"? I know one earlier reply said that it was, and another said that it wasn't, but neither really provided any evidence to support their claim.
These phones are brand new. My first one arrived directly from China in the mail over the course of 3 days.
My replacement one came right out of a brand new box (I watched them unwrap it and put my old phone back in it to be sent back to Apple).
Perhaps it's a problem that goes away over time? Maybe not entirely, but perhaps it becomes less noticeable?
Regardless, I won't be returning this one for this issue. It's not annoying enough to me to warrant waiting an hour at an Apple store. It bothers me that a "premium product" might have such a widespread quality issue, but it wouldn't be the first time.
I miss Steve...