You can also screen cap the QR Code and they can scan it right from your phone. I like it. It does get crowded but I think that's part of the concert atmosphere.
I don't like how crammed it gets in there and it's super loud, but it depends on your preferences. With the e tickets, you can either keep the code on your phone to scan or print it out and they'll scan the paper.
Thanks! Your answer is awaiting moderation.