there can be surprising variability. Like if the goths or hipsters take over a park one day you could be in a world of hurt. At Disneyworld it can take awhile to go to another park, unlike Disney CA where you just jump to DCA.
I didn't use the ride-by-ride schedule. I found that a little too rigid for a vacation. I hear others live by it though.
If your spending thousands of $ for the trip then another $10 for touringplans.com is worth it.