We did Disney this past June/July, staying at the Poly from June 29th through July 6th. We took advantage of an AP discount rate at the resort and found the crowds to be heavy, but manageable. We took advantage of early EMH when available and made sure we were at each park at opening. We stayed until 1 pm each day, when it really started getting hot, then headed back to the resort to take a nap, enjoy the pool, have a late lunch at one of the monorail resorts, etc. and didn't return to the parks at night, instead, watching the fireworks from the beach of the resort. Our typical touring schedule runs like this, as we have two little girls who still need to take their naps, so going commando style is not an option for us...to tell you the truth, it never really has been.
I do have to warn you. Do not get stuck on Disney's internal roads in the few hours before the fireworks begin on the 3rd or 4th. It becomes a huge traffic jam and we almost missed the 4th of July fireworks on the bus coming back to the Poly from DTD.