Pretty useful dictionary. Includes loads of local proverbs and very good transcriptions. The author has written other books about Gulf Arabic and is known as a leading expert on Gulf dialect.
The way the entries are written is very practical and straightforward, and usually includes thorough examples.
I have a couple of small beefs with the book, which on the whole is a work of excellence and indispensable to Gulf scholars, being the only dictionary around for the dialects of Bahrain, Qatar and the Emirates.

First, I find it a little too confining to organize words by their roots, when numerous loanwords have no Semitic roots.
In addition, consonant alterations can cause problems with this system. I was looking for qatam and later found out that it was listed under ghatam because Qafisheh’s assistants frequently pronounced qaaf as ghain. The dependence on the root system also results occasionally in duplicated entries, like the loanword 'rijiim' ("diet"), which is listed on p. 259 (under root "r j y m") and p. 286 (under root "r j m") with the same meaning.

My second big problem with this dictionary is that it often multiplies senses of words. For instance, 'rijaʕ' has 7 senses listed:
1. return, come back, come again
2. recur, come back, return
3. resume, begin again
4. go back, revert to, become again
5. (with 'ila) depend on, rely on
6. go back, be traceable
7. (with ʕan) to withdraw from
For this entry, examples under 2 and 3 were virtually the same, and in 7, the addition of a preposition doesn't seem to justify another sense. In many cases, Qafisheh probably added multiple senses for practical reasons, because the word has more than one translation in English—but on linguistic grounds this isn't a good guide.

Other minor problems:
There are quite a few minor typos, especially in the transliterations, but I suppose that should be expected in a specialist dictionary of this length.
The book seems to be missing some locally Qatari terms here and there, since Qafisheh mainly worked in Abu Dhabi—although the preface to his reference grammar notes that he did indeed do some fieldwork in Qatar. Having learned some Qatari Arabic, I quickly came upon terms which weren't in Qafisheh's dictionary.
The book also seems inconsistent in certain places when it comes to transcribing epenthesis. That is to say, there are four-consonant clusters in transliterated phrases when four-consonant clusters are generally assumed to be inadmissible.

This book is a great start, and I hope that someone in the future can put together a dictionary of this dialect grouping that is a little more complete and consistent, with the same practicality of use. ( )