As far as I can tell, these are some of the main differences between the BFA (BVA at SCA) degrees....
NAS places a much stronger emphasis on Drawing as a key subject. First year is 9 hours of Drawing a week, (out of 25) and in second and third year it remains a key subject, at 6 hours a week. All of their studio majors are more what would be considered 'Fine Art' (Ceramics, Painting, Photography, Sculpture, Printmaking) and so they don't offer any contemporary 4D art, or design option.
In this sense, the NAS could be considered a bit more of a traditional school than COFA and SCA. They follow a more traditional style of teaching art (strong emphasis on Drawing as the basis of all art, lots of studio time under the direction of an artist tutor).
COFA is a lot more open with it's BFA disciplines. They offer; Drawing, Painting, Printmaking, Photomedia, Sculpture/Performance/Installation, Time Based Art, Ceramics, Jewellery and Textiles. They also seem to put a stronger emphasis on the contemporary and conceptual.
Because they offer a total of five different undergraduate degrees (not including double degrees) and are part of UNSW, they are probably a much more diverse institute. You're not just working along side painters and printmakers, but also object designers, fashion designers, web designers, graphic designs, sound and video artists etc. Also including people from other degrees at UNSW taking General Education units at COFA!
At SCA, I think everyone receives a broad education across a mixture of disciplines in first year. They also have a drawing program - computer, experimental and life/observational. Theory mostly revolves around theories of art practice.
Then, in second and third year, students branch off into their single studio major. However, the school places pride on it's ability to offer broader interdisciplinary study.... so you're not just stuck in Painting, Photomedia etc. They generally branch off into three areas - Fine Arts (Painting, Printmedia, Sculpture) Media Arts (Photomedia, Electronic and Temporal Arts) and Object Art and Design (Ceramics, Glass, Jewellery and Object).
I know they're more 'contemporary' than NAS, and I think they might put a stronger emphasis on studio work than COFA.
Anyway, they all have their pros and cons. I'm aiming for Art Ed at COFA, but if I was to decide to do a BFA or BVA, I'd probably go for SCA myself. I really really love their campus and studio spaces. It's all very spacious!