What does it take to create a smartphone design classic? For the HTC One M9, the answer is relentless refinement, improving what worked in its metal-bodied predecessors rather than chasing the latest trends. The smartphone spec arms-race is relentless, however, notable as much for its hyperbole as the minimal attention span of would-be buyers in carrier stores. If you can’t make your case in seconds, you’re going to lose the sale. Amid fierce competition, HTC doesn’t exactly have the greatest track record of playing up its strengths and capitalizing on its advantages. Has that changed in the One M9?