Just got back from a trip last week opinion on the July crowd was as follows:
MK - Crowded as ever. Long waits on the popular rides. Major congestion in Fantasy Land.
Epcot - Was very light crowds and very few people for the closing shows. I stayed at Boardwalk and was able to grab extra fast passes in the evening with no problem for Frozen, Test Track, and Soarin.
AK - Pandora was busy. FOP was still a 3 hour late and at once point the line was out to the bridge area coming from Africa. The rest of the park was not bad.
Hollywood - Very crowded due to the opening of Toy Story land. Most of the shows were more or less full and rides like RNR and the new Toy Story had no late night fast passes available. I chalk this up to the new land opening and would see this slowing down within the next couple months once everyone gets their fix and the realization comes back that Hollywood just does not have much to offer right now.
The Brazilian tour groups were also back in full force where they were lighter the last couple years. Some of the groups were 30 or 40 strong These groups will run you over and blow past you in line without thinking twice, and have no problem congregating in the middle of a walking path stopping all traffic. This was terrible in Toy Story land, but there is not much Disney can do.
Interesting POV. We were there July 4th week and here's mine
MK - We were shocked that we found wide open space in Fantasy Land. Expected congestion between Petter Pan and Small World and there was non. Completely open.
Epcot - Shocked at how empty it was in WS for the 4th. The rain made it hard to judge for the fireworks themselves but even leading up to the storm at 8:50, it was pretty empty in WS.
HS - We got as many FP for Alien and TSMM as we wanted and even found a 5th for Slinky Dog. The area was only mildly full. There were openings for Jedi Training as late as 4:30 PM
AK - Seemed standard crowds, similar to all other days at AK. FoP standard is to the bridge coming from Africa every day of the year, since opening day, when the park opens. Then it dies down to a normal, 2 hour wait.
As to the 15's, there was a VAST, MAJOR improvement in their behavior. They were quiet and polite each time we encountered them in the park, and we saw more groups than we'd ever seen before. They were abundant but something has been done to curtail their behavior in the parks.
But what we saw last week was nothing like New Years or Spring Break, or even Fall Break. Those times were way, way more crowded. OP doesn't mention if they've ever been before or not, so not sure if they have something to base it on or not