I agree with the "proof" vs. "resistant" statement...I also agree that "a glass is a glass" as mentioned in one of the previous posts makes a strong point. Some materials may be tougher/stronger/weaker, but at the end of the day they are not indestructible and hence we should be expecting it to eventually be subjected to "wear and tear".

Just sharing my opinion. I'm sure that the N9 is not the only product that uses this, and there may be varying "toughness/weakness", but there.

We just need to be realistic/practical and not be too scientific/technical about it because there is the human variable where, no matter how we compare, we all have different usage styles, environments, amount of care taken, etc.