What a difference a year can make. Now that Intel's Skylake processors are widely available, desktop, tablets, and hybrid convertibles are all being refreshed with the latest hardware. Lenovo, for example, recently introduced its Yoga 900. Though the nomenclature has changed a bit, this machine is effectively a revised Yoga 3 Pro. The unique watchband hinge should all but give it away; it's the token feature on a potent, high-powered machine that acts first and foremost as a laptop, and secondarily as a slate...