The book is like the spoon, scissors, the hammer, the wheel. Once invented, it cannot be improved. You cannot make a spoon that is better than a spoon... The book has been thoroughly tested, and it's very hard to see how it could be improved on for its current purposes.
Going to contests back to back, World Tour and Primes, I've noticed a lot more things with my surfing that could be improved for my heats to improve. Staying focused throughout all of those events for months at a time is hard to adjust to but definitely fun.