Basically, the Centurion is a better frame (I know, I know. But really, it is.) with more stable geometry and will almost certainly ride more smoothly. The Bianchi has better components and will probably 'feel' faster if not quite as comfortable (even if it isn't any faster at all), and will probably need less in the way of updating.

The Centurion's got soul. The Bianchi's got a good name.