i have gotten most of the way through this book by now, and it is by far the best book on arabic i've seen. i'd recommend it even to those who are considering literary arabic [aka modern standard arabic].
 the dialect presented is conservative and unifying -- the grammar is that of a typical modern dialect but the words are essentially in the same form as in the literary language, without the complicated phonetic changes that characterize many of the dialects [e.g. egyptian] and create additional headaches for learners. the authors have also tried as much as possible to eliminate regional words and forms in favor of more universal, standard and/or literary forms. the result is that arabic speakers from all over should be able to understand you easily, and transition to literary arabic should be easy. [imo your total time learning literary arabic this way will be *less* than starting out directly with a literary arabic book, due to the huge inefficiency of learning in an unfamiliar script, as all literary arabic books make you do.]
 i have spent a lot of time studying 10 or 12 languages by now and seen a lot of very bad language books, as well as taken a course on language-teaching theory [which showed me what a horrible state this field is in! there is a total disconnect between theory and practice, which leads to a huge proliferation of ludicrously bizarre theories -- check out "suggestopedia" for some real laughs.]. so, so many books follow theories that dictate what you should *NOT* do -- never explain grammar [berlitz]; speaking only, no reading [pimsleur]; don't use the student's native language [the "native" method]; don't translate words, but let the students guess at the meaning [see al-kitaab fii ta:allum al-:arabiyya]; don't transliterate; etc. in my experience all these "don'ts" do is slow down getting a basic grasp of the language ["communicative competence"], and create lots of frustration. "teach yourself gulf arabic" is one of the few that does exactly what it should -- it focuses primarily on communicative competence, and makes use of any and all methods to make learning easier. one of the biggest is that they transliterate rather than forcing you to learn arabic script -- in my experience learning a language in an unfamiliar script takes at least 4 times as long. each lesson presents dialogs, vocabulary, cultural tips and grammar in an organized fashion, and the progression of vocabulary and grammar from lesson to lesson is logical and thoughtful, with the essentials coming first. particularly strong are the grammar explanations and the "notes" that explain unfamiliar constructions and usages as they occur in the dialogs -- the explanations are clear and to-the-point and do a great job of presenting what's important without burdening the learner with unnecessary complexity. the dialogs are kept interesting by focusing on various aspects of arab life, and dovetail with the explanations in the "cultural tips" sections. there also also well-done intro sections/appendices on arabic pronunciation, script and verbs.
my biggest complaint: all of the "teach yourself" books have terrible bindings, suitable perhaps for novels but certainly not for learning books. even if you carefully go through and stretch out the binding, the pages come loose very easily.