Nice to see another old guy on the board, next month I am driving 340 miles each way to see Iron Maiden so I feel your pain. I have never seen Maiden and have listened to them heavily since 1984 so I feel it must be done, especially as Seventh Son was one of my favorite albums and 340 miles is about the closest to me they have ever come. Fortunately I know people in the town I am going to and on the way back so it's not so bad.
As for sitting versus standing, I had a seat at the Slayer concert last year and this year I had to stand and actually preferred the standing experience. I guess I just can't properly headbang in a chair although I was perfectly happy standing at the back of the standing area as I am too old for the real moshing stuff.