I agree on MK being super crowded, and we did not get there until 7PM.
We started off the day with EPCOT, and it did not seem too bad, but then again it's so much bigger than MK, it gives people more room to spread out.
We did not have much of a touring plan as I am not a big believer in following a tight schedule, we are more of the 'wing it' family. We went in and grabbed fast passes for Test Track first, then went to Mission Space where the Orange stand by was only 10 minutes. After that we did a Perry Secret Agent Mission in World Showcase. Those are pretty neat, like a little scavenger hunt or the Mid Ship Detective agency game on the Dream or Fantasy. We could have spent all day doing those going from country to country, but after the first one in the UK we had to use our TT fast passes. We did not get the opportunity to design our own cars, maybe because of the fast pass lane. Not sure as this was the first time we had been on this since the redesign. We then went to Spaceship Earth and had about a 15 minute wait for that. Our son still loves this ride, he made a funny face when they capture your picture and we all had a good laugh when they put that on the screen. It was closing in on lunch so we headed to the Land Pavilion to pick up our Soarin Fast Passes, which were for 6PM. Even the boat ride in the Land had a 30 minute stand by at this time, so we just skipped that and had lunch there in the pavilion. My wife and I split an Asian stir fry dish that was pretty good.
After lunch we headed to DHS via the boat at the back entrance of the World Showcase. We got super lucky and got on a boat that was waiting and we left in under 1 minute. It was a nice way to get off your feet and relax a bit, as the whole trip is about 20 minutes, with all the stops at the resorts between the 2 parks. We were happy that DHS did not seem too busy. We were able to ride RNR, ToT and Star Tours in pretty short order. Star Tours was a walk on, we had Fast Passes but they were not even needed so we kept them for souvenirs. It was only about 4PM, but we were getting hungry so we looked into the waits at the sit down table service restaurants. The 50's Prime Time had a wait of 40-50 minutes. We had eaten there before so we headed to the Sci-Fi Dine In to see how the wait was there. NO WAIT!! We got right in and had a great time. We had never eaten there before and thought it was pretty cool. Bryce even got a Drivers License for being in the Drivers seat of the car we were in. We then spent some time pin trading. A CM told us to check out the trading board in one shop near the Muppet area, and Bryce was able to find the 5th in a series of pins he was missing so we were very happy they told us about this board. It was behind the counter and we had to ask for it. As soon as others in the shop saw this they all crowded around. I reminded Bryce to save a few traders for officer pin trading on the ship, and with that pin trading was done. In the end we had traded about 10 pins at DHS.
We took the boat back to EPCOT and arrived just in time to use our Soarin Fast Passes. The Land was much less crowded now and the boat ride was a walk on. We did that first then went to Soarin. This is still my wife's favorite ride in all of WDW.
It was getting dark by now and we had the decision to stick it out in EPCOT or go to MK. We chose poorly and went to MK. The ride on the monorail over was painless enough, but as soon as we went in MK it was a sea of strollers and ankle biters. Main St. at the front of the park looked like Bourbon St. during Mardi Gras. We contemplated just turning around, but I made my own path through the crowd and DW and DS followed in my wake. We got back and walked on the Haunted Mansion and PoTC. The two rides we really wanted to do. The back of the park was not as bad, as everyone was up front to watch the castle show. We debated on staying later, but we were all a bit tired by this point and rather than push ourselves to the point where no one is happy, we headed back up front for the buses.
Even though they had the bus times on the hour, it sure seemed to me they were just continuous at this point. The bus line was about half full, and we only had to wait about 10 minutes before we were on a bus and headed back.
We all fell asleep on the ride back despite the volume of the cartoons that were on the monitors.
We usually go to WDW in August, and despite the near surface of the sun temperatures, the crowds are not that bad. Plus I like HOT. We had never seen MK as busy as it was the day we were there. I don't mind the crowds, I just don't get why groups of people like to stand right in the middle of walkways and stop to discuss their life's plans. Move off to the side people. I always try and walk right through the middle of groups like that. It's like driving slow in the passing lane on a multi lane highway. DON'T DO IT.
All in all, the day was a 10 of 10. We had a great time.
DH and DD (16) went to DHS for 2/3 of the day and said it was awesome - multiple rides on all the biggies with very little wait. They met up with us around mid-afternoon at MK and spent the remainder of the day there. We treated ourselves to the Fireworks Dessert Party since we knew the crowds were expected to be big that day. It was a great (non-crowded) way to end our day. While we thoroughly enjoyed our day, I am in no rush to go back quite yet!
