The most fun was not on the field, but watching my son pretending he was playing football. Once he grew tired of that, he decided (with some prompting) to roll down the hill. His aim was perfect... he rolled right through a muddy area in the grass.
There was one element that was specifically impressive. You have to know how a practice runs to know why this is impressive, but before "team time", there is a time for "individual break out" time where specific positions practice their individual roles. I saw the linebackers practicing and noticed Urlacher. He was not in his position but he was running the scout position. Here is one of the most publicized players on the team, easily expected to have a huge ego, running drills on the scout team. It wasn't just once, he continued to get back in line and run scouting drills. Team... pushing your teammates to succeed to their best, not just getting your best.