Kamab :
Maximum white luminescence and max contrast ratio are going to have a direct correlation, aren't they? I think the reason they didn't mention a display upgrade is because there isn't one. They simply got their LCD panels from a different vendor (probably cheaper). I can see the camera upgrade being handy though.
The IP4S to me feels like an attempt by apple to lower expenses by leveraging existing architectures (IP4) and components (processor from iPad2) to drive profit margins.
The only reason someone with an IP4 should upgrade to an IP4S is that due to extreme demand you could probably sell back your IP4 for 350-400$ and know that your 4S will retain value for a long time as well.
Yes and no. I dialed back luminance for some other lab testing and we certainly still saw a difference in color temperature and gamma. This kind of goes back to the yellowing issue seen on some iPhone 4s (plural not 4S), which may be possibly related, but the replacements that Apple sent out were suppose to have their yellow tint fade away over time. At least that was the story... The bottom line is that there is a difference between the two models.
I suppose one could argue that its a cheaper panel. The one thing that the microscope shows is that it definitely is a different panel. This isn't just a weird chemical film that's plaguing a batch of Retina displays. This is actually a different panel at the subpixel level, because the subdomain structure has also changed.
7200 K is closer to the standard 6500 K, but without proper color calibration though, I'd say blue looks more natural. That's also reflected in the "standard calibration" most manufacturers use on their LCD displays.
I don't know about the only reason to switch. There certainly are many reasons not to use an iPhone, and I would be remiss to recommend one to everybody. In the US, the real problem is the inflexible carrier plans and the requirement to buy a data plan. Of course, this is a problem with all smartphones, so not just applicable to the iPhone.
Cheers,
Andrew Ku
TomsHardware.com