IMHO it's worth it if you are interested in a touring plan. There plans are great and save hours of line waiting. I usually use an adult highlights plan and subtract any attractions that I'm not interested in and that is perfect for me. They have times of all the shows, park opening and closing, menus for restaurants, ride descriptions and ratings by age group to help you pick what to do / what not to do. // Now if you are just looking for picking what time of the year to go and crowd levels, easywdw.com is all you would need.
When we pay about $100 per ticket (I usually just do one WDW park per year), $13 to make our day more fun is well worth it.