This could well be the best two-way dictionary of any language pair anywhere. As an avid student of several foreign languages (incl. English and German) for 20 years, I have come to know what constitutes a first-rate dictionary. It is nothing short of a masterpiece. I had been using a predecessor edition (2nd ed., 1991) for some 10 years, and even when it was published it was the best of its kind and constantly on my desk. This 4th edition raises the bar by featuring improvements across the board. The benefits derived from the increased computerised analysis of the huge word corpora Bank of English and Deutsche Textbörse are increasingly visible. Vorsprung durch Technik, indeed.
1. This exhaustive dictionary embraces, on 1000 pages in either section, every register from formal officialese via the standard language right down to vulgar slang. But it is in the real-life language where Collins has the finger right on the pulse. Many word entries are awash with examples of usage/idioms/set phrases/proverbs as actually used by natives as well as their natural translations. (I wish there were a way to download all this information into my brain because I would be able to handle any situation in flying colours.)
2. Inclusion of German words like Kardanwelle, Rochade, das Pull-Down-Menü, Überlaufanzeige etc. indicate extensive coverage of specialist terms in many fields as well as loan-words from the 90s which now part of daily life.
3. The English section is equally impressive, listing e.g. cyberpet, establishing shot, trick or treat, decontextualize, nuclear reprocessing plant, memory expansion card, look-in, supergrass, wicked (UK slang). The word "go" and its associated phrasal verbs have an astounding range of translations.
4. Idiomatic phrases such as "to get away with sth" and "jdm etwas zumuten" which are contextually dependent are given several alternative and appropriate translations.
5. Certain bon mots and expressions which are used mostly in situations on one side of the Channel (or those whose counterpart is much less colourful!) are well translated.
Examples: set piece, pub crawl, single-track mind, car-boot sale, off-the-record, stomping groud, pipe dream; Stammtisch, Führungszeugnis, Geheimtipp, Kuschelrock, Dreitagebart, Wohngemeinschaft, Dunkelziffer, nicht mehr der jüngste sein etc. In fact, even "Ich schau dir in die Augen, Kleines", the classic line from the dubbed version of Casablanca, is listed. Hut ab!
6. This edition includes an audio CD with pronunciation (because they understand that there is a practical limit to phonetic script). The layout has been given a face-lift with 3 columns per page instead of 2 resulting in improved readability.
7. The dictionary's vast scope, depth and usability for both English and German learners and speakers (in equal measure) leave virtually no room for valid criticism. Yet some words and expressions seem to have escaped the researchers' keen eye for detail (so far); missing English words are e.g. polenta, present/current value (Fin), brown-noser, case-sensitive. Im deutschen Teil sind die folgenden durchaus geläufigen Wörter nicht aufgeführt: Quereinsteiger, Marktabschottung, Kasslerbraten, Regelwerk, verhandlungssicher, Töff (CH). But this is nit-picking.
Summa summarum: kudos to the team of meticulous professionals behind this work for having brought out the Mercedes S-Klasse - with all the optional extras - of dictionaries.
Buy this dictionary - you may still be using it in 2012.