My answer probably won't help you. When I reflect on the pictures, I agree with Jessi. The second picture really gives a hint as to how massive that fall is and the power of the water. But I have to say that when I first paged through the images in the lightbox, my gut reaction was that I liked the first one better. It's hard to explain gut reactions but I think it's because the first tells a story of a photographer and you get their story along with the beauty of the falls and the rainbow. In the second, I think my gut thought the person was a distraction - probably because they are so small.
So I'm like you, undecided. I think maybe in a slide show where people won't have a lot of time to reflect, I'd probably go with my gut. If it was a gallery showing, maybe I'd choose the reflective one.