We probably won’t get a true sense of How Durable the Sony Xperia Z is until it’s released. The fact that it comes with a glass back has some people concerned on the fragility of the device. We've already seen a Drop & Water Test Video, although we’d like to see another onto concrete to see how the glass fares.
Until then, check out the video below, where the Xperia Z is subject to a few hard knocks on the corner of the basin and then thoroughly rubbed with Sand before being washed clean in a bath. Overall the phone shaped up pretty well.
To See the Hard Knock at the Corner of Basin, then switch to 0:50 - 0:60.
Then switch to 2:40 for Sand Massage & Water Bath Test.