Re: Phone appearance
"What is the advantage of incorporating this material into the phone itself, as opposed to allowing a user to fit a case of their own choosing?"
Building the phone like that is better than using a case because if it's part of the phone's design, then you can avoid the various issues that cases introduce that make it a bit more annoying to actually use the phone. For instance, cases make buttons and jacks more recessed than they would otherwise be.