They built an IMAX theater at Great America, an amusement park in Santa Clara, CA years ago. I used to get season passes to the park when my kids were still children and we’d make sure to see the latest IMAX film at least once a year. Some of them were absolutely amazing while others were just good. I think all of the films were enjoyable and all of them had at least one spectacular scene where the IMAX size was put to full use.
I’ve been to a couple of IMAX theaters outside of amusement parks and its usually been worth it.
Seeing a film on such a large screen is great. If you sit near the center of the theater so that the screen takes up most of your peripheral vision the affect is quite spectacular. When they do things such as flying your brain can get tricked into feeling like you’re flying.