You've got more than just weight to factor in here, as others have suggested. I can share my own personal experience by describing three road bikes I own and ride all 3 each week. The first is a vintage steel frame with classic European road geometry, weighing in at about the same as your Bianchi. I like the feel of the steel with this bike; it soaks up road bumps and vibration very nicely. However, it does not climb or accelerate as well as the other two I'll describe.
The second is a 16 lb. full carbon Specialized S-Works Roubaix. This bike is heralded as light, fast, and comfortable. Indeed, it is faster (much faster than I have a right to ride), climbs extremely well, and the geometry is stable and comfortable. However, I prefer the road feel of the steel when it comes to comfort. While the carbon does suck up the vibration, the larger bumps get transmitted pretty directly to the rider.
The third bike is a slightly heavier 18 lbs. combination of Reynolds 853 steel and carbon fiber. It is also built around classic European road geometry. While not the lightest, it climbs better than average and accelerates just a bit less quickly than the full carbon bike. However, this is the bike that gets the most miles because all around it is the best mix of comfort, speed, acceleration, stiffness, and climbing ability. Frankly, in many ways it is more bike than I thought it would be when I built it (I ordered the frame and built it up with Ultegra).
I guess the point of all of this is that just frame material or bike weight shouldn't be the determining factor, based on your stated goals. I've made the decision that a 10 minute test ride is not sufficient to judge the bike's characteristics. And, if I'm laying out more than a grand for a bike, I want to be able to put at least 20 miles on it riding in areas that are similar to the ones on which it will be used. There are subtle ride characteristics that you just won't uncover in a ten minute test ride. Several weeks ago I was checking out a Lynsky Ti bike, and took it for a short ten minute ride. I was smitten. So, I asked if I could come back and take a longer ride. The dealer was happy to oblige. After 22 miles I realized that this is a great bike, however, it would probably still play second fiddle to my current favorite. If I had made the judgement on the 10 minute ride, I would have sworn that this was the ideal bike for me. I may still purchase a Lynsky in the future (there are other things I like about Ti and the company), but not because I'm looking for a better ride.