The new book is very pretty, hardcover with lots of glossy, full-colour pictures. In addition to the actual game rules, it has articles on painting and a nice section on building Gary Chalk buildings for the Old West. The book is pricey, but you can see from the production values where the money went.
It's up to you to decide if you want to spend the money on a pretty book with lots of pictures. If all you want is the rules, you are probably further ahead staying with the free edition (if you can still find it).