In my experience, the language study books in the Colloquial Series are of uneven quality. Some seem to add confusion in attempting to throw light on difficult grammatical concepts, while others make grammatical complexities understandable to novices to the learning language, Colloquial Estonian is in the latter category. Moseley does an excellent job of making unfamiliar concepts of Estonian grammar comprehensible to English-language students. He also should be commended for teaching the Estonian language in the context of contemporary Estonian culture and life-style. I highly recommend this book.

A series of more or less negative opinions in the internet made me buy the book.
In order to cope you will have to bring along at least some basic knowledge of
Estonian or else the going might get rather tough.
On the other hand chronical setting in awakening free market societies always
tends to influence the matter to present itself in an optimistic way.
English speaking public of some education and a sound grammar base will enjoy
the manifold and rather uncommon aspects of structure and morphology
explained in the wake of quite reasonable features that are not
far-fetched at all.
In spite of the fact that it is more than 15 years old the book is - for the
right kind of people - absolutely commendable.

I expected a book and CD and only got the book. Useless.

PROS:
- None

CONS:
- Use of a non-native speaker (his voice sounds suspiciously similar to that of the author's) on the recordings. He reads and speaks Estonian as if he were telling a story to young children since he seems to enjoy using exaggerated intonation, length and volume. None of the other speakers are as bad or patronising as he. I cringe when hearing his shouting or mangling of Estonian.
- Inconsistencies between dialogues' scripts and recordings
- The sequence of recorded sections (especially for pronunciation) doesn't match the sequence printed in the book.
- Inadequate English-Estonian glossary. The Estonian-English glossary is a little better in comparison.
- Insufficient amount of exercises.

"Colloquial Estonian" competes with "Colloquial Slovene" and "Teach Yourself Slovene" as the worst self-instructional language course that I've used. It also is a warning when using courses that are designed by teachers or authors who are not native speakers of the target language. I'm thankful that "Teach Yourself Estonian" (it was designed by teachers who are native speakers of Estonian) is now available and it is a marked improvement over Mr. Moseley's creation. (Incidentally, Mr. Moseley is now a teaching fellow of Latvian at SSEES (School of Slavonic and Eastern European Studies). As far as I could tell his main links to Estonian were that he had earned a master's degree in Balto-Finnic linguistics and focused on reporting/analyzing Baltic affairs while working at the BBC. There's no mention if he had ever gained substantial and meaningful experience in teaching Estonian anywhere)

Unfortunately Colloquial Estonian is still the only self-instructional Estonian course that is widely available for many people. The competition isn't very comparable to begin with. Aside from the newly-published "Teach Yourself Estonian", Juhan Tuldava's "Estonian Textbook: Grammar - Exercises - Conversation" has a much better presentation of grammar but was never designed with audio and has a pitiful amount of exercises. Felix Oinas' course "Basic Estonian" is dated and modelled on a course used at the Defense Language Institute. Its cost (approximately $300) and comprehensiveness (the textbook has 393 pages and comes with 32 tapes/CDs) also make comparisons with the shorter "Teach Yourself Estonian" and "Colloquial Estonian" unsuitable.

The author shows every sign of being a student of Finnish who has dabbled in Estonian on the side. He certainly does not understand the language enough to be writing a book about it.

1. It has already been noted that he does not understand certain consonant changes ("gradation") that are critical to speaking and reading Estonian. I would say it is worse: He thinks Estonian's three-level gradation is the same as Finnish's two-level system. When his model quickly falls apart even in his own examples, he lamely mumbles something about "exceptions" and hurries off the topic, leaving the student no wiser.

2. Learning verbs from this book means the student will struggle to use an Estonian dictionary. Moseley is either unaware of the dictionary form of Estonian verbs, or he consciously refuses to accept it. I can see a case why the -da infinitive should be the default form, as its Finnish counterpart is. But it isn't, it never has been, and a book for beginners is not the place to challenge reality. As it happens, I don't think Moseley is a linguistic bomb-thrower. I think he simply doesn't realize that Estonian uses a different convention than Finnish.

3. Estonian's fourteen noun cases can be introduced in any of several perfectly logical approaches. Moseley uses none of them. Oblique cases appear willy-nilly from the very first dialogue, with very poor explanations and sometimes no explanation at all. I don't see how any student could not be frustrated by that. One never gets the sense that the author understands how to teach and present a foreign language.

4. On the plus side, the appendix includes a very useful paradigm list.

But that's not enough to make it worth buying the course. You might as well flush your money down the toilet. It'll be faster and you'll learn nearly as much Estonian.