I am just coming to the end of a 12 month distance learning course at Cabair, and I would certainly not advise shelling out on a whole extra set of notes, although with the possible exception of the OAT MET cd. Cabairs notes, while not fantastic, are quite adequate and they are being reviewed, updated and improved all the time. If there is anything that you find difficult, the instructors are on the end of the phone and are uniformly excellent. I have been told that the great advantage of the OAT CD is that it gives animations of weather phenomena, and that really helps get to grips with a lot of the stuff such as the Jetstream and frontal systems.