I was trying to get a lot of people to clap in the balcony, where I was sitting in balcony 4, especially during the Hymn.
I just got home a few minutes ago and had some time to reflect. In terms of the no photo/video policy, the security people didn't enforce it before the show or the intermission like you said. They only enforced it during the actual performance when the band was playing. I still manage to sneak a few pictures and videos, but nothing worthy of posting (unless you like staring at the back of the people's heads in the row in front of me).
The second Act was really awesome. Moment of Betrayal was awesome as well as The Walking Shadow/Our Last Farewell. James got the vast majority of the crowd to stand up during Our New World.
Overall, the band was killer throughout the night. Petrucci messed up a solo late in Act 2 (barely), Jordan play a few wrong nights at the beginning of Astonishing (like Nonstop said), and James had a rough few lines in Lord Nefaryus. Other than that, 10/10 show. Sound was great (I was in the balcony) and I could hear everything clearly (the keys were kind of quiet at the beginning of Act 2, but they corrected that fairly quickly).
Honestly, this is definitely a top 2 show when I've seen them. They played very well and I wish I could go see this show again.