We had a vacation in July. We did encounter the Brazilian tour groups (they were wearing it on their shirts) and they were fine for us. I guess that when crowds become larger in combination with the extreme heat, everyones' patience grows thinner. We did have issue with smokers. Our DS was in the stroller and almost got hit in the face with a ladys' ciggarette in a crowded area. I reminded her that smoking was in designated areas, and she almost started a fist fight with me. I was in the "bring it on" mood, as my husband brought me to my senses. Also, while trying to see the fireworks at MK, this entire family came less than 2 feet infront of us with her huge golf umbrella and cut off our view. It was so funny that they did this, there was no one else in the immediate area. I was so fuming that I shouldered her and stepped infront of her. She was completely clueless, and thanks again to my DH's calm manner, He again talked me out of being irrate and we had to step back about 50 feet with another great view. I still couldn't believe the behavior of these people. They were definately decendents of Sweden or Russia or Slovakia or Africa maybe. They were probably from Idaho or Ohio or something that ends with o.
The larger crowds bring in more "bad eggs", but also more nice folks.The nice ones are the quiet ones following the few rules of WDW and not demanding attention. We'd go again in July, but we'd make it a mini trip. It's fun to take advantage of the long park hours and the water parks this time of year! Pros and cons either way.
Input is MUCH appreciated!!!! 
