My wife and I stayed at Les Chambres d'hotes de Magali for two nights in September 2012, and I can't say enough positive about our stay. Magali and her husband Etienne are wonderful people and instantly made us feel at home. Our room was comfortable (and of course clean) and tastefully decorated as was the rest of the B&B. Breakfast (traditional french) was excellent and the other guests were happy to engage in conversation with this not perfect French speaker. Magali was right on with her restaurant recommendations, and I really enjoyed dinner at the family-run place right in Cassano.
The location of the B&B is calm and relaxing, with great views up to the mountains. It is perfect if you want to be away from the coastal bustle around Calvi and Isle Rousse yet not too far away from either town or the beaches. Also a good location if you plan on hiking town-to-town in the Balagne region. Magali said the path is accessible right from town but we drove to begin elsewhere.
In sum, if I ever go back to Corsica, I'll certainly go back to this B&B.