I bought the NKS book within a couple of weeks of its release in 2002. I started reading it then but got put off by the Preface and Introductory chapter in the book where I could not digest the huge dose of Wolfram's ego we were subjected to. That and work pressures meant that the book was subjected to dust in a corner of my bookshelf.
I started reading the book Sunday. A couple of things have changed that prompted me to read this book. A hot sunday eve in Trondheim, without a book to read can be pretty depressing - particularly when you are tired after a long cyle ride. I just finished reading Castle of Crossed Destinies by Italo Calvino and needed a book to read. It was a choice between Godel, Escher, Bach and NKS.
My reasearch requires me to think out-of-the-box as the field I am working is a work in progress for over 30 years now with no definite end in sight. Thus a new approach would definitely do me good and I thought NKS may be called for.
I have thus far read 100 out of the 1200 pages of the book (which could have been considerably reduced if the Is in the book were omitted). I realize that Wolfram has ignored work of other researchers in the field, or has appropriated their results as his own. The book nevertheless gives a good background and explains the field very well and thus provides a good summary. The whole area of cellular automata is interesting and the book is a good and interesting read.
All said, I think the book's title overreaches in calling it a New Kind of Science.