In my opinion this is the middle one of the three currently available Gaelic self-tuition books (see my other reviews). Although I didn't rate it much at first, as time has gone by it has become the one that I most enjoy dipping into.
It is by far the fattest of the three, at 344 pages, but the typeface and layout make it look a wee bit cluttered. It is divided into 23 shortish lessons, with a sensible progression of material and a good structure. The vocabulary lists are annoying in that they present entire phrases most of the time, but despite this, the explanations of grammar are clear and comprehensive, much better than the Colloquial book, though not as good as the In Twelve Weeks book. The dialogues are very lively, both in the book and on the CD, and there is a great set of exercises in each lesson.
The audio material is not as comprehensive as the Colloquial book, there being just one CD, but it is so much more listenable than the Colloquial. There is also some information about Gaelic culture, very welcome lists of place names, forenames and surnames, and a good Gaelic-English vocabulary list (but not the other way round). Like most Gaelic books, it falls down very badly in not having any printed pronunciation.