My tandem experience is limited to steel and Al. But I've put a lot of miles on steel, ti, al, CF, and even boron ceramic metal matrix (a high tech al alloy).

I really like my CF Giant TCR Team Advanced, so I appreciate the advantages of CF.

When we decided to get a high end tandem, we decided to get an Aluminum Co-Motion. There were several reasons we didn't get a Calfee CF tandem.

1) I really bought into to all the positive stuff abotu cO-Motion as a tandem bulider. I know Calfee has a great reputation, but Co-Motion seemed to be a bit more focused on tandems.

Not being able to ride either, I just felt like I had a little more comfort level in knowing what the CO-MO would be like.

2) Our priority was rigidity, and respnsiveness. We were willing to sacrifice some comfort if necessary.

3) Price/ Weight Trade off. For about $8000 you can get an Al bike from CO-Motion that willbe just about as light as a CF bike from Calfee or Santana.

4) Timing. I wasn't sure we could get a custom bike from Calfee in our time frame.

5) durability traveling. I'm not one to put down the durabiltiy of CF, but scratching/dinging it, does worry me a bit travelling.

Riding the bike it meets our expectations for stiffness. You do feel road vibration, more than our Steel Burley, and based on riding CF singles, I would bet more than a well done CF tandem. And I've noticed in a few rides, that a little less pressure is enough to smooth out the initial relative harshness we felt in the ride.

So IMHO, it all comes down to priorites. If performance per dollar is key, and outright performance is more important than ride quality, I think you can make a very good case for either the Robusta or the Macciato( depending on team weight).

If price is not an a object,and ride quality is high on your priorities, I'd tend to lean toward CF. and in slightly differnet cicrumstances we might have done that ourselves.