I had a good time there myself. Arrived around 1pm and entered after half an hour waiting at the southern gate (Wilson). I stayed for the whole thing, but missed some of the late afternoon acts -- Blue Rodeo through most of The Guess Who -- looking for a friend, back at the southern end.
Here are some of my observations:
The crowd was mostly young. It felt like the median age was 24.
People were quite well behaved and things went off without a hitch. I saw very, very few signs of trouble
People were also quite sober because the beer was so hard to get. On the other hand, second-hand pot inhalation was continuous.
There were some very crowded places where people were jammed into lines that wouldn't move and were continuously walking across areas where people were trying to sit on their blankets. After a few hours of this, I could see some people getting really stressed.
Strangely, you could get more room if you moved forward -- contrary to the complaints of the blanket sitters who were ordering everyone to quit trying to move up. For the evening I settled into a very comfortable position with a direct view of the stage. (Mick Jagger was still just a speck in my binoculars, but I could see him.) This area may have been more clear because everyone was standing, or because people were stuck in the jam behind and blocked by some fences and buildings.
You could see the speed of sound. I noticed that the screens further ahead would change before the screens closest to us, and yet the screens were properly lined-up with the sound. This was because the screens (and local speakers) were timed to match up with how long it takes for the sound to travel.
It wasn't very loud. You could talk the whole time.
Scared by the rumours of tough trips home, a heavy and continuous flow of people began to exit at the end of AC/DC.
After worrying about water, I ended up with so many water bottles -- free and purchased -- that I brought some home.
Food was easy to get at the back, but I didn't get to see Ralph Klein. (I had two $6 beef brisket sandwiches.) Food was much harder to get for people who wanted to find their way back to the same space afterwards.
Show ended at midnight. The exit was fine. No crushes, no over-crowding. Just a large moving mass. It took us 70 minutes to walk to Yonge and Wilson (York Mills subway station). By the time we got there, there was plenty of room on the subway and I was home in another 20 minutes.
I heard that the TTC was doing interesting things like running southbound trains on both tracks. However, given the way things worked out they could have used more buses to shuttle us to Yonge. Wilson was clear past Bathurst and I saw parked "Out of Service" buses.
AC/DC revved up the crowd and The Stones were a good show. Now I remember how Mick Jagger stays so skinny. The Timberlake-Jagger duet was good and it's too bad I missed Justin's 20 minutes on stage.