That is a stunning photograph! (The reaction of my office when this flashed up) This stood out for me as everything looks so seamless. Each fall and run of water is there and the merging of the moving water is not overly blurred. I also like how the focus is in the picture, almost tucked out of the way. It is well balanced composition between the water, falls and green banks and the choice of a wide photo shows the shot off well.
The green is maybe slightly overpowering in parts of the shot - but I think that is just how the shot was processed and it doesn't detract from the overall effect.
No problem - I'd recommend getting one. They can help enhance/adjust colours a bit and can remove reflections in the water. Even quite cheap ones from Amazon or eBay work well and I almost always have mine on my lens.