I have to agree with most of the pros and cons others have mentioned for this book. I purchased this book for a recent trip to all three of these parks (four if you include Waterton, which is also mentioned in the book). The book does include information on the trails for the parks, but it is briefer than what you would find in a regular trail book. Very small maps are provided for the trails, so you would need something more detailed for actual trail use.
One feature I particularly liked was a table for each park showing several trails and features for them. This table included the usual info such as hike type, start location, distance, time, and elevation gain, but it also included features and facilities. In the latter two categories the table would indicate things such as wildlife watching, waterfalls, restrooms, whether restaurants were nearby, etc.
The book also includes a lot of information on the nearby areas; things to do, places to stay, and so on. I wasn't as interested in this material, but it did seem to offer a lot of alternatives to just hiking or driving around in the parks.
Overall, I found plenty of useful information in the book and thought it was well worth the price.