Sony's flagship smartphones may not have set the world on fire so far, but the company is making another concerted push in 2013, launching two top-end phones with near-identical internal specs. The Xperia Z is the main player here, with refined mirrored panelling across the sides and back and a machined power button being the only physical undulation from the 5-inch oblong. Sony's put in its latest tech from across the family, being the first device to house its Exmor RS sensor ca