I think dark rides/attractions are always going to be questioned. Every kid/family is so different in what their expectations are... what scares one child may be hysterically funny to another.
We usually do ITTBAB once per trip, and that's usually enough for our family. The darkness and special effects have never bothered my girls, although we're not fans of being stung.
That being said, we just lean forward enough so that it doesn't really affect us. We hold our nose during the stinky part, but the show itself is very well done. We have encountered a few scared kids during our visits, and I feel for those children, but I've learned to tune those out (luckily, my kids have never freaked out).