The nineteenth century presents a great increase in publications of guitar methods. Most authors of the time published several versions of their works. Fernando Sor, perhaps the most prominent guitar composers of the time—whose Méthode is regarded today as the most important of the period—only published one edition. However, Napoleon Coste took on the task to do a second account. The literature reviewed shows substantial existing information regarding background, type of text, tone, and contents of Sor's work, but comparisons to date are not substantial. Therefore, there is a need to compare these two texts side by side to yield a complete view of their pairing. The existing negative views of Coste's edition hinder the importance of Coste's work as reference to Segovia's publication of Sor studies, and as a clearer pedagogical application of many of Sor's concepts which are sidetracked by his response to criticism and his elaborations in matters beyond his main subject matter. I provide a comprehensive review of Sor's method, an outline and a consideration of his concepts. Then I offer a complete English translation of Coste's method which is inexistent until now. The comparison follows pointing at differences and similarities. Results show that Coste clarifies and complements many of the principles in less text and simpler language. He modifies certain others either to approach Sor's practice or to depart to a newer standard. He offers his own lessons and sections to apply Sor's concepts. Coste's text heads towards a pedagogical synthesis of Sor's method, but it is incomplete because he omits some concepts without leading the readers to consult Sor. Coste's pedagogical and practical relevance is fundamental for modern standard techniques.