Well, we just got back from our three-day trip to Disney. Thanks for the last minute input!
Some observations (we went with 7 and 4 yo girls) :
We did not stay on the resort as this was wrapped around a business trip for me - we stayed at a hotel near the convention center, about a 20-minute drive to the park. Next time we will stay on the resort We will also be their longer - this trip was a week-long trip but we did not do Disney until Thursday-Saturday. It would have been easier to get going a little earlier, and take a mid-day break, if we were a little closer.
We initially rented a single stroller for our 4 yo, and pretty quickly realized we needed a double - easy enough to trade in. Having a stroller made it much easier to get from place to place - once you got to a location, you could park the stroller and ride/watch all the attractions in the area, but with 90+ heat, and crowds, being able to put both kids in the stroller made life much easier for everyone.
As noted, we went with young girls - so Princesses were an important part of our agenda. We did not plan the trip until about 6 weeks ago, but it might have worked out for the best - we did not get the princess breakfast at the castle, but we did get a princes breakfast at Epcot - Norway castle - and the girls had a blast. You get a staged photo shoot with Belle when you go in, and then once everyone is seated, there is an opening procession where the kids get to parade around the restaurant with the princesses, and then once you eat, the princesses all come by the table to sign autographs and take photos. Then there is a closing procession with the princesses.
Toughest line for princesses was Rapunzel - about a 90-minute wait, almost all in the sun. We passed on this the first day - but she is our older daughter's current favorite, so we knew we would tackle it later.
We did use TouringPlans as a guide, and it was helpful in planning each day, and throughout the day using the app to track wait times.
It took me about a half-day to really figure out the fastpass system, but once we did, everything was a breeze. Touringplans also was helpful in figuring out which rides you needed to get fast passes for ASAP.
We did convince both kids to ride Splash Mountain and Thunder Mountain - our younger one is more adventurous, but is 40.01 inches tall, with tennis shoes and a hat - but she passed every measurement test. Turns out they loved both rides, and we rode each about 5-6 times over two days. (Although half-way through the first time on Thunder Mountain, my older child turned to me, and said: "I don't even know why they allow kids on this ride!") By the end though, she really enjoyed it. I think we rode everything in Fantasy Land, and Frontier land, and a couple of things in Adventure Land. We saw Mickey's Philharmagic - liked that. Spent some time meeting characters for photos and autographs.
Second day was intended to be split between Epcot and Hollywood studios, but we got a little bit of a late start, and by the time we got Fast Passes for Soarin' the ride time was 2:00, so with some of the other rides, and the princess breakfast/brunch - we ended up staying at Epcot for the day. Kids rode Soarin', Test Track, Living with the Land, Nemo (liked), saw Captain EO (did not like), (I got to ride the space mission ride with a fast pass, and I rode test track a couple of other times using the singe rider lane - about 20-minute wait, and we spent a bit of time touring the country pavilions - not really kid favorites, but my wife is from Germany, so she wanted to spend some time there, and we lingered in a few other countries - bonuses for seeing Rapunzel's Tower, and also getting photos with Aladin and Jasmin. Ate dinner in Mexico, and watched the evening show illuminations.
Third day started at Hollywood studios - fast pass for Toy Story (this and soarin' were the only two rides that I saw sold out of fast passes over our three days). Watched little mermaid show (Get a fast pass, since it does not count against your limit), which ended just in time to get in about a 20-minute wait for Playhouse Disney show - really recommend this if your kids watch Mickey Mouse Club playhouse, Handy Manny, Little Einsteins, Jake and the Neverland Pirates - cute live action show. Spent some time in the Honey I shrunk the kids play area. We could have spent more time here - but had to get back to MK to get in line for Rapunzel, so we left shortly after lunch.
Spent the last afternoon at MK - sent my wife to get in line for Rapunzel, while I took the girls to get fast passes for Splash Mountain - that helped pass the time. Rode some of the kid rides in fantasy land with 15-20 minute waits. Went to Tomorrow land to ride Orbiter and Buzz Lightyear - both with very small waits. Used fastpasses and short lines to ride Splash Mountain and Thunder mountain a few times - the last time we were on Thunder Mountain, the ride broke while we were on the ride, but in the station, so we got a free fast pass. Ate dinner spent some time in Adventure land, before using up last two sets of fast passes on splash mountain, and a fixed thunder mountain.
Things to do next trip - stay on the resort; stay longer, to allow for multiple days at each park. Meals were not a problem - with young kids we were not looking for a dining experience, as long as we had a place to sit, out of the sun - and we never had a problem. Water was an issue - we took water in everyday, but it did not last long - frozen lemonades were a god-send. We did not appreciate it going in - but learned quick enough, to have an autograph book for the kids. Stroller, even if you think your kids have outgrown them, is a good thing - these were long days, and getting from point A to point B was much easier with a stroller. Parks were crowded, but manageable. Use fast passes on popular rides. Some rides you have to get fastpasses for when you get to the park - but then use the down-time on rides with shorter lines. We made only one "error" - waiting in line about an hour the first day for the Winnie the Pooh ride - understood the value of the fastpass after that.