I was at the starting location of the final stage of last years race (Dawsonville). I got there about 2-3 hours before the race started and got over 80 excellent photos. Had plenty of time to see the bikes and talk to team members.
There were only about 1000 people at the start. The finish was swamped with people. If I recall correctly, there were over 250,000 people at the finish.
My advice - Be at the start (Gainesville and Blairsville) and you'll see a lot more than you will at the finish.