Understand going in that iH15 is designed for a very specific purpose: though it works with all of the Dock Connector-equipped iPods and is affordable enough to pair with any of them, it’s unquestionably best suited to the iPod nano and its owners. The primary feature of what starts out looking like a white plastic cube is a color-shifting light system that’s found inside, emitting a soft glow that shifts from orange to yellow to green,…