Link for people to check it out:
http://www.bianchiusa.com/06_castro_valley.html
I think I'd be frustrated with a single 42-tooth chainring, and a 3-watt headlight that only shows when I'm moving. Although I think those are supposed to be 5W actually. Given the choice, you may be better off spending the $100 extra for the Volpe and then get really good accessories to fill it out. If it were me, I'd trade out the Volpe's tires for some light 700x28's and light tubes, get a light non-suspension seatpost, and go from there.
Think about it... with narrow tires and a decent riding position, a road bike can really haul. I don't know about you but I don't like running out of high gears. I run a 48 x 11 high gear on my mountain-commuter, which is certainly slower than either of those Bianchis, and I use the 48 x 11 every day. And when I'm tired, it's nice to have the 36 and 24 on hand on the way uphill to home