I read through this whole thread, and I decided to add some of my thoughts and opinions about WDW as someone who goes to
Disneyland at least once per year and has been to WDW twice, both times in early April:
-Churros are not good at WDW. Don't get your hopes up. In fact, just don't get any.
-Test Track is a really fun ride. If I compared it to RSR, RSR would win hands down. But don't compare them. They're both great.
-Make sure to have some ponchos at all times.
-Haunted Mansion is really good. We love the upside-down stairs. But we do prefer the style of the mansion's exterior in Disneyland.
-Water is not good at WDW. Don't drink water from taps. Even soda from fountains tastes weird sometimes.
-Splash Mountain is fantastic! I wish ours at Disneyland was as good.
-We don't love the feeling at Hollywood Studios. The rides there are some of our favorites, so we enjoy our days there, but I wish we enjoyed the atmosphere in the park better (coming from someone who loves DCA).
-Space Mountain is painful, and the music is bad. We do it once per trip. At Disneyland, we ride it at least once per day.
-Everest is great. One of our favorites. Don't be afraid, just enjoy it!
-Disney transportation is not good when you are trying to be somewhere at a certain time. We stayed at Bay Lake Tower the first time we came to WDW, and we prefer being just offsite with a car or Uber. It's fun to ride the monorail around midday, and we will also try out the Skyliner for fun, but we don't rely on Disney transportation.
-Pirates can't compare. Just try to enjoy it for what it is.
-Jungle Cruise is fun because it's a bit different and longer.
-Everyone says it, but it's true: people are far more laid back and relaxed at Disneyland.
-Humidity is a killer. Hoping for decent weather in December.
-Enjoy eating around the world at Epcot. This was some of our best food at WDW both times.
-We've never had anything very good to eat at Magic Kingdom. Didn't think Be Our Guest was worth it at all. Don't go into Magic Kingdom hoping for mint juleps or beignets or churros.
-Atmosphere at Animal Kingdom is great, but it's always hotter here. There are very few rides, but there's much to see and enjoy while walking around.
-We have better days at EPCOT when we don't rope drop. We like to come a bit later and stay until closing.