I think that Chambers is a virtual necessity for Azed (or Mephisto) - you are doing exceptionally well to get as far as you have without it. Not just for the definitions of the solutions, but also the indications in the word play, which normally match a definition in Chambers verbatim (eg 32a today - one of the Chambers definitions for 'dead' is 'without vegetation').
I have both hard copy and PC versions (the PC version comes on CD-ROM and is then installed onto the hard disk - but don't do what I did and throw out the box together with the licence key, a slight - £12.99 to be precise - problem when I came to reinstall on a new PC!!). I like the hard copy for use at the breakfast table, but the PC version is good for the wildcard search (for instance a search for '?reg' will return 'areg' and 'dreg'). I also like the full text search, where a search for Botswana will return 'pula' (the unit of currency) and 'kgotla' (an assembly of Botswanan elders); and the anagram finder is a boon when I know what the letters are but can't be bothered to work it out! Peter Biddlecombe's review on Amazon (http://www.amazon.co.uk/The-Chambers-Dictionary-Thesaurus-ed/dp/0550101918) is perhaps a tad harsh, but he's right about the punctuation thing (it doesn't handle accents too well either). I have to say that I wouldn't be without them both, and the electronic version (which includes a thesaurus) is particularly useful when it comes to clue writing - it dates from 2005, but very little has changed between that and the 'paper based' 12th edition. Hope that helps!