I've been to Tuscany ten times over the past decade and have always used Cadogan, to my mind still the best out of the scores of other guides that have sprung up since, including the Rough Guide. They may not always get the phone numbers right, but the authors' make each corner of this beautiful region come alive with their knowledge and witty writing. The new 6th edition has a greatly expanded section on the Marches-a lovely region that no other book in English covers very well at all.
When some years ago I was given by an American friend of mine a copy of this guide, I soon noticed that many information (e. g. telephone numbers of museums, names of bus companies) on the area in Tuscany where I live were outdated. So I wrote the authors a short letter with new numbers, names etc. Two weeks ago I saw the 6th ed. of the guide in a Florentine bookshop, but the wrong numbers, names etc. were always the same! They were not corrected!!! I wonder why!