The first thing I can say about Dobson's textbook is that it far beats the textbook with which I was introduced to Greek in 1994. When I was at Houghton College, we used Story and Story's Greek to Me. Although it's a cute title for a Greek textbook, I'm afraid that was also the result--Greek was still pretty much a foreign language for me. The main feature of Story and Story's textbook was these little cartoon drawings that were meant to be used as mnemonic devices to learn vocabulary and grammar. The only one I remember was the first one in the book for the word ἐγείρω, which means "I raise up." A Robin Hood character is raising up an 'egg-arrow'. That one was actually pretty helpful. The others were not.
My contention is that mnemonic devices work best when the learners create them in their own minds.
Perhaps it would have worked better if the cartoons were in color like the one here, but the black-and-white line drawings had too much detail to easily make them out. My time would have been better spent using my own brain to learn Greek than trying to figure out what somebody else's memory aid was supposed to mean.
The main feature of Dobson's Learn New Testament Greek is that it has was designed for non-native English speakers. This means that grammatical terminology is only explained after the forms have been introduced in exercises that illustrate how they fit within the context of sentences. For example, the terms 'nominative', 'accusative', 'genitive', 'dative', 'masculine', 'feminine', and 'neuter' are only introduced in ch. 12, pg. 67, after these things have been introduced in successive chapters with only the use of English glosses.
I do appreciate the attempt to teach Greek in a way that follows some natural language-learning principles. I hope that the abundance of practice exercises in each chapter proves helpful to my Melanesian students who so frequently learn skills within their cultures by doing them, not by reading about them.
Because of the avoidance of grammatical terminology, the section headings in each chapter normally do not contain any description of the section's content. It seems that the book was intended simply to be used as a step-by-step procedure. This lack of descriptive headings, however, makes the book difficult to use when one wants to go back and review earlier content.
Certainly for people who speak English as a second language, the use of grammatical terminology could amount to information overload. Since I am teaching national Bible translators and pastors who regularly consult secondary literature, however, one of the goals of the course is for them to become familiar with the standard terminology. So in class, I use the terminology, and I remind them that they will not be tested on the terms. But I tell them I want them to be familiar with it so they have some idea what others are talking about when they come across these words in commentaries and translation helps. I usually get a classroom full of approving nods.