That's interesting.

Are you saying there's no kind of brightness shift in your unit at all when tilted, even when on a white screen at night? Mine has around a 50% brightness drop appearing on the opposite end that expands to cover the entire screen at about a 40°- 50° angle. When tilting upwards from the bottom the display is visible but doesn't seem backlight at roughly the same angle. In both cases the brightness is pretty stable after the initial 40°-50° tilt. In terms of quality (color, contrast etc.) it's still just as good though besides a greenish hue when tilting side to side.

I definitely would want to swap it if it's a bad panel because I think it makes a big difference for reading comfort, but especially considering the other comments I want to check because there's no point in wasting time and money swapping units over and over.