Sony may have just redefined its Xperia brand to encompass more than just smartphones, but that doesn't mean its limiting its number of Xperia models. In fact, sources are claiming that the OEM is about to unleash a fourth "Xperia X" model. After the base Xperia X, the beefier Xperia X Performance, and the more budget-friendly Xperia XA comes the Xperia X Premium. If that name reminds you of the Xperia Z5 Premium, then you'd be correct. It takes after its "predecessor" not by having a 4K screen but by having the first HDR screen on a smartphone.