Lots of people come once. Never known someone to come for a second trip.
Seriously, some will, some wont, some love it, some hate it. You cant please all the people all the time.
I took up a couple, she was quite before but keen, he was very vocal about looking forward to it. He was sick, turned out he always gets travel sick.
She was fine, upside down, straight up, straight down she loved it all.
Take you que from the passenger, keep an eye on them and be sensitive to how they are feeling.