I just booked ATH-VCE on Air one, through KL, with AZ flight numbers.
Price seemed fair: 120 euro roundtrip, including booking and credit card fees. This was about 10 euro less than alitalia.com, and about 20 euro more than flyairone.com.
Main advantage of booking this way: Flights earn 50% miles for FlyingBlue, and one piece of checked luggage should be free.
Wonder how these flights will be. If lucky it should be possible to use the lounge and priority lane at security. Does Air One do anything special upon boarding or in flight for elites?