Palmer's Bornu Sahara and Sudan was fun at first but quickly turned into a depressing chore. Unlike Sudanese Memoirs, which mostly consists of primary sources, this volume pounds on the reader on the head with the various unsubstantiated theories of Palmer on the origins of Kanem-Borno and African civilizations. As one would suspect, everything is connected to ancient Middle Eastern, Berber, Nubian, and Abyssinian migration or influences. Palmer, per usual, relies on questionable linguistic theories to connect these various influences which eventually led to the formation of Kanem and neighboring kingdoms in the precolonial era.
After reading half the book, we decided to skim the remainder for interesting sources, information or changes in Palmer's translations of some local materials. For example, some of the mahrams appear to be translated differently in this work than Sudanese Memoirs, and one gets the impression that some of the Kanuri songs and girgams quoted in Bornu Sahara and Sudan were not included in the previous work. However, for Palmer's version of the Diwan and some of the speculative theories on particular mais in the Sayfawa dynasty, one should still consult this work.
Just keep in mind that it's not always clear where Palmer derived his information and some of the translations could be shoddy and misleading, especially when tied to his penchant for random linguistic connections. For instance, his theory connecting the name "Organa" for Kanem in medieval European maps is almost certainly incorrect, just as most of his work reflects the Hamitic Hypothesis and its hyperdiffusionist perspective.