Memory cards weren't the problem - I had my laptop to transfer images. Batteries were the issue. I had exactly enough battery power for three days of heavy shooting.

If I get asked back, I'll do it. Also thinking of trying to use this as a cost-saving exercise on all the indoor metal festivals I go to.

I would buy a better lens, as from the back of the tents I didn't have enough pixels to get a good image. And probably a couple more batteries.
Or... I COULD buy a new camera... you know? This one's 9 years old now, so SURELY I can be excused?