Paula's books are meant to be used as a guide. There have been products that I have disagreed with Paula's review, but there have been a lot more where I agreed with her.
Mainly I use her books to make better informed decisions about where I am going to spend my money. Before I read her books, I made my product decisions based on the advertising. Now, I can read Paula's reviews, read the ingredient labels and make a better-informed choice.
For example, my favorite foundation (sadly discontinued) was one that Paula didn't like at all. But it worked for me and one of the reasons I bought it was the sunscreen in it was one that Paula recommended.
Paula's recommendations for skin care are what cleared up my face. I developed bad acne in my 30's and nothing the dermatologist gave me worked for more than a couple of months and even then, cleared maybe 1/2 - 3/4 of my skin. One of the products I use daily is a 2% BHA gel, either Paula's or another brand that she recommends in one of her books. The cost is about the same, I use whichever is easier for me to buy. (If I am ordering @ Paula's I buy hers, otherwise, off to Walgreens.)
My favs from Paula'a are: 2% BHA gel, creamy lipsticks, eyeshadow singles, blush. I'm thinking of trying her moisturising gel, my birthday was this month and I subscribe to her newsletter, so I was sent a code to get 10% off my purchases this month. Decisions, decisions! (I'm trying very hard not to order more lipsticks, I have way too many!)
Meg