Just got back from a trip over July 4th. There were quite the number of tour groups, but in their favor, most of those I saw were very well behaved. Exception to Argentina when they were playing just recently (and that was just a simple "Ar-gen-ti-na" chant that did not last forever, I doubt it lasted more than 5 minutes.) And the second being a group of girls getting happy with the rain - dancing on main street with their shoes off. Although someone must have said something as they headed out to they buses because playtime quickly ended and all shoes (except for those of one of the older members of the group) were quickly placed back on the feet and walking resumed.
What I did see were rude individuals, mostly American, judging by language and accents. To them, I apologize, I did not understand it was your vacation I was interrupting when the cashier asked me where I was from and answered. And to another couple, when I side stepped oncoming strollers and cross traffic, I did step in front of you as you attempted to run around me and get to the Phillarmagic queue line (I was not headed for) before me. Thank you for pointing out that I was the rude one there. I decided for the remainder of our trip I'd sit out the foot traffic in the stroller parking areas so I would not encounter you again. (Just kidding, and simply making a point... the tour groups did none of this.)
Although I thought it curious that the tour groups would elect to travel to Disney over one of the most crowded times instead of waiting a week to come, they would not impact my decision to visit again over the holiday week.