Good enough. I used this to study for the Kentucky insurance adjuster exam and I did pass on the first try.
This book is perfectly adequate for the general knowledge and standardized policies and coverages.
There was an online supplement for state specific knowledge. I am confident that none of the questions on my test referenced any of the information in the supplement. Luckily it wasn't a huge part of the test, but they were very specific questions on state law that were reduced to pure guessing if you didn't know that particular tidbit.
Overall, an effective study resource, but don't trust the state specific materials.