There's a ton of useful information on the site (think of an online, interactive guidebook). But the best part is that all the information YOU need for YOUR dates will be all in one place. You'll have the park hours, parade times, EMH days, and most importantly, the recommendations and explanations of which parks to go to on each day to avoid the crowds.
I can't believe the number of people who've complained about his site (I know it is confusing though) and the money they spent, etc. It's no more expensive than a normal guidebook and I think just as informative in general information, and WAY more informative in specific time and up-to-date information. Plus, if you aren't happy, I've read of many people requesting their money back and getting it immediately so you really don't have anything to lose!