I quickly read through the sequel to Captain Alatriste, Purity of Blood. Overall, I thought that the book is a better book to read on vacation than in my somewhat limited free time. I also thought that the first book was better, since the lack of plot development, the extended descriptions, and the slow pace seemed better suited to the first book in a series.
I did enjoy the depth of portrayal of 17th-century Spain, although I am not in a position the historical accuracy of the extended ruminations on Spain's downfall. However, for fiction I tend to prefer books with more interesting plots or with better character development. Well, I guess you can't expect everything from a novel.