We wrote about this earlier, but now lab tests confirm that the ION-X glass display on the Apple Watch Sport actually lets more color through than the Sapphire display found in the mid-range and high-end Apple Watch and Apple Watch Edition models. The tests by DisplayMate show the lower-end model performing better under ambient light. In a dark room, the difference would be less noticeable, but it is significant because it adds to the storyline that the entry level model may be more desirable.
First, aluminum weighs less than stainless steel. This means that the Apple Watch Sport is lighter, and presumably more comfortable, than the midrange model. Also, there are numerous reports of the stainless steel models suffering scratches, which, while they can be polished out, is a nuisance for such an expensive device. Sapphire is second in hardness to diamonds, so it is less likely to scratch, however it can be more susceptible to fractures. Combine these concerns with the ambient light issue and the $200 premium to move from an Apple Watch Sport to the stainless steel Apple Watch with sapphire display is hard to swallow.
It also could explain why Apple hasn't embraced sapphire as the display screen on the iPhone 6. In addition to the falling out with their provider of sapphire, if the color quality of the iPhone were to suffer, it's hard to see Apple switching to sapphire. And screen fractures are already a big enough problem for Apple, so increasing scratch resistance at the expense of resistance to cracking would be a step backward.
