Over the decades I have collected several 12/A12 backs, 5 total, which now seems like overkill as I use only 2 (low speed b&w and high speed b&w). Lately I've been using the A16 and A16S backs more. The 16S backs were dirt cheap ($20-40) and give a different way to use the Blad for creative portraits. Just my thoughts. RandyB