This book is not intended to serve as a textbook in linguistic analysis, as any scientific linguist will readily see. The author has attempted to use linguistic analysis as a means of helping beginning students to acquire a knowledge of New Testament Greek
After introducing the alphabet and pronunciation, he begins to discuss linguistics. In Chapter 3 'Linguistic Structure' , Chapter 4 Grammatical Analysis, Chapter 5 Parts of Speech, Chapter Nouns, Gender, The definite Article. Then in Chapter 7, Sentence Structure. When describing sentences, he uses something similar to Funk (Nn - V - Nd - Na) to describe the dative sentence in Greek (§85) saying it equals S-V-IO-O in English. He also uses this kind of notation to talk about the conversion of the Active to the Passive §117).
While the linguistic terminology may seem overboard and unneeded to many students, what impresses me is that Goetchius is very sensitive to word order and has many Greek examples (all with corresponding translations). There are some parts of his book which imoho are lacking, such as a good discussion of the middle voice, the meaning of the aorist aspect. But what I have found that no one has a better description of phrases. He has a whole chapter on questions (Chapter 39 Questions). His description of πᾶς is the best out there. He gives many examples of how it is used with and without the article, before and after its noun. He has Chapter 41 Coordinating Conjuctions and Chapter 42 Subordinating Conjunctions. He has a great description with examples of how οὗτος and ἐκεῖνος are used with / without the article and their various patters (before/after).
His book, like Funk's A Beginning-Intermediate Grammar of Hellenistic Greek http://www.ibiblio.org/bgreek/project/funk-grammar/pre-alpha/, which can be found on the B-Greek website, has a separate workbook.
Funk also starts out talking about sentence structure, and about Structure words (semantically lacking) words versus Content words (semantically rich). It seems these two authors are from the same school of thought on many areas (Structural linguists - which was disproved by Chomsky - or Phrase-based grammar? or some other similar school). But what I find what I get from both of them is a good number of examples (especially in Goetchius). They focus on the sentence structure and patterns which seems to be lacking in many first year grammars.
I've found them both very useful