This week saw the debut of two ARM-powered tablets by old rivals. One eschews traditional desktop input methods; the other embraces them. One occupies the high end of pricing in its class; the other is competitive with the market leader. One had the engineering goal of fitting in one hand; the other comes with a kickstand for being set on a desk or table. But perhaps the biggest contrast between the iPad mini and the Surface RT approaches is how well they take advantage of the hardware and software momentum of their predecessors.
