For the iPhone 5/iPad Air design language, white looks very classy. The chamfered edges, the silver TouchID ring, looks the shizzle.
iPhone 6 design language is ugly, so black is better as it hides some of the details.
My iPad 4 was black. My iPad Air is white. My iPhone 5/5S was white. My iPhone 6 is black. Having had plenty of experience with both on an phone and tablet, I don't find the bezels to be distracting at all. I will say the white does hide the finger prints better though.