I was recently at the Frankfurt Musikmesse and I played some of these basses. I have no connection to Cosi, but I was so amazed I had to write this post.
They have an endorsement from Barre Phillips. They have models that are all CF (ebony board and maple bridge, though), as well as spruce top models, and foldable (removable neck) models as well. I didn't find the spruce top version very interesting, but the all carbon was really neat! I found it really special on the E-String, which I could make speak with the delicacy, clarity, precision, and punch I get from a D-String on most nice wood basses. And this was with Spirocore! (Are the French aware that there are other strings besides Spirocore?) The instrument was very even, from the open E to the highest notes on the G, and as loud or as soft as you could ask for at any place in between. At the audition I gave it on the floor at the trade show, I found it wonderful for orchestra passage work, Bach suites, and concertos, although I can't say how ideal it would be for jazz (it would depend on your tastes). The price seems to me quite fair, although they are not exactly giving it away. I really can't stress enough how impressed I was without doing something embarassing
Again, I am in no way connected to Cosi, but if I were shopping, I would buy one in an instant. Just don't know how the orchestra would react. Bringing a synthetic bass to work would be only slightly less shocking to them than wearing a flashing neon green codpiece! After they heard it though, I bet they would deal.
Robobass