I lived in Paris for two years (2004-2006) but didn't begin to shop until I found this book (recommended by Amazon). Often in Paris, the store windows don't really show much about what's inside, but this book tells everything you want to know before getting on the Metro. Every description was accurate. The shops were where they were supposed to be, the merchandise was as described in the book, and prices were close on the mark.
Every Saturday I mapped out where I would go based on "the book". I found that if I read the shop descriptions, I could tell in advance if I would want to find them, so I would check off my "must sees". Along the way I made notes in the margins about the shops, and also what else was in the neighborhood. I didn't find the restaurant reviews particularly helpful, and wish they were left out to make room for more shops.
An unexpected bonus: looking for "the book" stores often lead me into streets and neighborhoods far from my usual treks, and MORE shops! The sightseeing hints were excellent also. I never went out without this book, and my co-workers borrowed it until it became available at WH Smith. I met Susan Winkler at a book signing there, and she was amazed at my margin notes (and probably at the tattered condition of the book).
Two of the specialty shops Susan praised were down the street (Rue Royale) from where I worked and I went into them at lunchtime at least once a week. My only regret is that my last month in Paris was the dead month, August, when almost every thing is closed, but I burned up the pavements for the six months preceeding. (I bought the book as soon as it came out in February).