I never want to see any concert of a band i am really into see open air. Lightshow sucks, sound sucks, maybe weather as well.
LOTB Hannover 2018 was okay, but still.
My experience is a little bit different. I want to experience Maiden ONLY indoors. They are better suited for
theater aspect of the show. Darkness, aura of the indoor arena, good visibility etc. Metallica is a different kind of a beast. I watched them two times on Death Magnetic arena tour - had a great time. One time open air in Tallinn, when they played Master of Puppets in full, and one time in Riga stadium. I had equally great time watching them in open air. They pull different strings of your soul. Music of theirs is better suited for big stadiums. Rhythm and crushing riffs.
Hypnotizing power, crushing all that cower...
I saw Maiden in Poland, on their legendary Somewhere Back in Time World tour (2008y.) It was a stadium show. I was very far from the stage. I liked the show very much, it was my first Maiden experience. Nonetheless, I had a feeling, that as a stadium experience it was not a 10/10. Wish i had seen them indoors. Also, I have seen Maiden on their Book Of Souls World tour, and three times on LOTB tours - all those shows were indoors. Had a great time. I had greatest time on TBOS tour for some reason. Best setlist, perhaps.