I went to the show last night, and actually, I was surprised how not loud it was. Granted, I was pretty much right at the front, and the main, big speakers in the venue were at my sides, and aiming behind me, at the main area of the auditorium, but still, given the warning, I was expecting it to be louder. It didn't sound any louder than the Astonishing Show did, where I was in about the same place, in the same concert hall.
I brought earplugs, but right from the beginning, it sounded way too quiet with the earplugs for me, so I didn't use them, and overall, the sound was quite comfortable to my ears.
For the record, I recently decided to take a chance on these ones:
https://www.amazon.com/Vibes-High-Fidelity-Concert-Earplugs/dp/B018WPOQSGSo yeah, they lower the volume quite a bit. I'd feel completely safe wearing them at an extreme metal concert.
I mean, it was loud, as a concert should be, of course, but compared to other concerts I've been to, where I'd sing along and wouldn't be able to hear myself even at the top of my lungs, in this one, I could hear myself singing along well enough, and I wasn't even singing at my maximum volume, so at least where I was sitting, it wasn't nearly as loud as I expected it to be.