Thanks to all for the comments.
Scott - I have been enjoying some of my water shots as fast shutter speeds 1/500 - 1/1500) but the images tend to carry a lot of detail and they have to be viewed on at a larger format. I agree that #1 is not that interesting at the scale available on the web but I quite enjoy it on a large screen. I am convinced that the size vs optimal viewing distance issue is dependent on image content. Does that register at all with what you have seen with your shots?
tom b - thanks for including the link. This kind of image is fun to play with.
Peter - It is the translucent character that I like about this one as well and what I was trying to capture for the 'mood' series. I came back to this riffle later in the day and the light was completely different. Like I mentioned to Scott, I think the motion of the water comes through better at a larger size.
Cheers - Chuck