This is an EXCELLENT dictionary.
Pros:
1) TWO WAY! For an incomprehensible reason, most Persian dictionaries seem to be one-way only, usually English-Persian.
2) DARI: Afghans often understand Farsi (Iranian) vocabulary, but you won't understand them well without a proper understanding of Dari. There are few (if any) good Dari dictionaries, so this makes this a must have no matter what.
3) USAGE: The dictionary actually points out the difference between most synonyms - but not all unfortunately.
4) PRACTICAL VOCABULARY: The dictionary is intentionally written for people interested in politics and every day work in Afghanistan, rather than for academics interested in the obscure words that show up in Persian poetry. Sadly too many dictionaries are written for the latter audience. (Not to say one shouldn't look into Persian poetry - it's wonderful!) This dictionary is thus ideal for aid workers, diplomats, and anyone else working on the ground in Afghanistan.
5) Well designed and typeset. Compact - the pages are dense but easy to scan.
6) Well chosen vocabulary - not many ridiculous or arcane words.
7) Lot of colloquialisms (including profanity!) and special section on idioms.
Cons:
1) As mentioned in another post, the pronounciation is only given in the Dari-English section, thus you sometimes have to look up words in the English-Dari section up in the Dari-English section for pronounciation.
2) Unclear vowel pronounciation. The author tries to help by putting english equivalent words to show what kind of vowel sound (e.g. what kind of 'a' is this? a as in cAt, bAre, etc) on the bottom of every page. But sadly it's not much help, and I'd prefer he simply used the standard phonetic alphabet.
Overall: A MUST-BUY for anyone serious about the Dari language.