Spending a day at your resort I think is actually really important. You're spending money to stay on site, you should ENJOY the resort! We just booked Coronado Springs, and they have one of the coolest pools (IMO), so we want to enjoy that. Also, after spending 2-3 days in a row walking 10+ miles, you start to get worn out. Now that I have a desk job, I think I'll get worn out pretty quick since my serving days are over and standing on my feet for extended amounts of time isn't something I'm used to anymore.
The first day of us being there, we get in around noon, plus the 40ish minute ride on the magical express, plus the check in process, so when its all said and done we wouldn't get our money's worth to go into the parks, so were going to change and head over to Disney Springs for some shopping and eating. Then the next day we can get up nice and early and utilize the entire day.