It’s no secret that Sony’s smartphone business is struggling. Competition has become fierce over the last couple of years, with continued innovation and lower prices causing trouble for market incumbents. Rather than doubling down on their flagship products, like HTC did with their excellent HTC 10, Sony seems happy to trundle along with minor iterations year after year. The new Xperia X series may not carry the same name as its predecessor, the Xperia Z, but there’s no mistaking these products for a revolutionary change. I've been testing the the top-end Xperia X Performance for a few weeks now and I've found it to be remarkably similar to the Xperia Z5 that preceded it. Considering the Z5 was the sixth derivation of the 3-year-old Xperia Z, it’s easy to feel this design is getting stale. Read the complete review.