Concurring with what's been already said, I took a stab at composing it the way I would like to see it. I would almost shoot vertical on this because there is a nice step-wise progression of water down the different levels to the bottom of the frame and that should be emphasized. I also think that if it is even a little bit bright, that brightness somehow flattens the image and makes it less three-dimensional. I've adjusted the brightness, sharpness, and cropped a bit, and actually ended up putting it more center just because it emphasized the pattern of the waterfall itself.
Another thing about nature scenes, I find even just a few leaves that are brighter than the others distracting (particularly the ones on the left of the original image. There should at least in my mind be very few highlights in a photo like this that would distract from the "movement" of the water. I always think in terms of a pastel painting and that everything should be balanced in terms of intensity.