Yeah there are a few hassles (shutle buses, lines, etc) but our daughter loved Disney from start to finish. We did 6 days of parks. Too many things to list, so here's the trip review focused on what to do with a young child (3 going on 4, loves princesses). These things are what she liked and didn't like. For adults- if you're going with a 3-year old and are at all focused on what you yourself like to do, you might as well stay home. Just view it through their eyes.
Day 1 and Day 6- Magic Kingdom- Loved Dumbo (went right away, no line). Liked Peter Pan, was scared of Pooh but there was no real reason to be (did that right away too for short line). Loved the characters in the circus tent (4 characters and AIR CONDITIONING). Liked the Barnstormer and wanted to go twice but later said it was 'a little fast'. The fairy character line was the longest but she liked it. We went to the princesses on Main St and Mickey after the parade and didn't wait at all! The 3 princesses were a highlight too. Liked the Magic Carpets, scared of the jungle cruise (it's corny but they say things that she didn't understand weren't real). Train ride was a good break. Loved the carousel, teacups, and Small World (go back to that part first!). A little scared of the Philharmonic 3D movie. Loved the Speedway. Liked Buzz Lightyear but was also a little scared of the silly aliens. Did Chef Mickey at the Contemporary- 5 main characters and actually pretty good food so good value.
Day 2- Epcot- not as much for a 3-year-old overall. Princess Breakfast was a giant hit...this was really well done. "Complementary" picture with Belle, and 4 other princesses came during breakfast. Not that interested in the country area except for the characters interspersed throughout (like Jasmine, Belle, etc). Had some fun in Innoventions. Surprisingly liked Spaceship Earth. Liked Nemo (only a short scary moment). Loved the Turtle Talk with Crush and she got to talk to Crush. Refused to go on Journey into Imagination (I might have messed this up by calling it the Purple Dragon Ride).
Day 3- Sea World- took a Disney break. She loved Sea World. Dolphin show was awesome, Orca show was great too. Sea lion show was a little dumb but still fun for her. She liked the tower, liked the aquariums, liked the amusement park rides (no lines), petted the stingray (surprise), fed the dolphins ($7, sort of a long wait, but when else can your kid feed dolphins). Adult note- we got all you can eat added to the ticket for ~$6...we had a big BBQ feast for lunch and had 'free' water and soda all day.
Day 4- Hollywood Studios- Also not quite as much for little kids but still a full day. Loved the Toy Story ride (get a fastpass immediately, maybe two if you can). This is similar to Buzz Lightyear but more toy-like, not scary, well-done. Liked Little Mermaid show (scary moments were as quick as possible). Beauty and the Beast show was love/hate (she loved the princess parts, but the scary fighting scenes were a little long I thought). Loved the Disney Jr show (this was the only show in the whole week with zero intense moments). She didn't like the Muppets 3D that much...it's a little intense at the end. Besides Toy Story, not that much for little kids besides shows.
Day 5- Animal Kingdom. Went to Kilimanjaro Safari right away and waited ~20 minutes. This was great for adults and kids. The reviews I had read mentioned a scary storyline but they must have done away with that because it was just animals and no story, not scary. The two walking trails were good for her. Dinosaur ride was good (just like Dumbo). Nemo was a great show. She got a little scared at a few parts but I thought they kept the scary stuff short and not explicit. By this time we felt we had traumatized her enough so we skipped the Lion King. We had also read reviews that the Tough to be a Bug show was scary for young kids so we skipped that too. Lots of characters here...the 4 huts were nice and out of the sun and the Pooh/Tigger/Eeyore part was nice too.
All in all- plenty to do for a kid this age and it's magical just to watch them turn each corner and see each new thing. A few traumatizing moments, especially in the dark shows, but she liked them. Plenty of rides she could go on. Characters were probably the biggest hit and offered a nice break from everything else. Fastpasses only really necessary for a few of the things that little kids like, and you can do well by going to those early in the day. Don't forget...it's not about you at all!
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.