The Z1 to be a quality image, carved from one piece and also has a decent weight. For me, a quality reference.
The flap for tight connections are also fine. So that was already in my Defy. But water resistance is a very cool advantage. So you can make underwater photos. Dare! (I've already written in my Tablet Z review: P)
The Z1 is fast and has very rarely hammered regard my application. I use it without Launcher third and bring it even sometimes its limits. So warm like my iPhone 5, it was never this.
Is impressive especially the battery life. The bombastic! Buy yourself the charger, then you must not always rummurksen with the cap.
Also Appintegration to write great at Sony. With Music Unlimited account you can already find neat Mucke and hear. However, the app requires an internet connection, also to reflect on SD stored music.
All in all I give a strong buy recommendation, even though it may be with me probably still takes a bit until I so happy forever ^^