The Sony Xperia XZ may be the brand's fourth flagship in the last two years, but it's been a whole year since it released the Xperia Z5 to critical acclaim at IFA 2015.In the meantime Sony has released the Xperia X, which we believed to be its latest flagship handset at the time – but it wasn't. The Xperia XZ is that phone.The Xperia Z line is now...