In terms of the debate about books versus journals, I think that like most divides both have their pros and cons inherent in the very nature in which they present their materials. While I generally try to use an equal balance of both in terms of my own research and work, I find that do to certain limitations in terms of availability or technical malfunction in the case of journals, I am often left to work with whatever is more readily available and relevant. I do not think that either is superior of the other and both serve the historian well in the quest for knowledge, references etc. Moreover I think that both serve essentially the same purpose in conveying ideas, arguments etc and are therefore invaluable to the study of history.
That being said, I have worked with a number of both and generally prefer the old fashioned method of analysing books in the tradition of historians of the past. While books may seem more impractical as well as generally longer and perhaps less concise, the idea of examining a computer screen all day somewhat bothers me. As well, the length of the book oftentimes leads to greater historiographies as well as more ideas presented in one medium. Therefore the focus is much larger, much more multi-dimensional and usually involves the use of more sources. Pragmatically as well, books are easier on the eyes after a long day of reading..
However as mentioned journal articles have their merits as well. While not as big as books, they tend to offer a more concise argument and are much more focused which leaves for less sifting through a book to find one particular idea. As well journals usually provide a detailed glimpse of the historical concepts in which they are writing in that they highlight the debate and framework of their analyses at the beginning or introduction of their works. Articles are however problematic in that tracking down an article that explicitly deals with an area of interest is difficult because of their narrow focus. Moreover availability is oftentimes an issue, relative to the school’s access to the article.
Overall both have many merits as well as a few follies, but it cannot be forgotten that without them, historians would essentially be starting from scratch—although some would argue this is a good thing!