I like the 2nd shot best, although it doesn't look bad, the reflection doesn't do much for the shot in this instance, I feel it detracts from the water splash, which is more the star of the show here. I read somewhere once that an exception for leaving more space behind the subject would be because there is something more interesting behind it than in front of it, like some action of some sort. Here I see some water action behind it and it looks great so that would be acceptable. But instead of trying to leave more space in front to make it "rule of 3rds" compliant, I would instead crop in from the right, leaving less room in front and putting the water splash and the duck equally on the vertical 3rds lines which would, imo, put more emphasis on that wonderful water splash. But, as always, to each his own! Great capture, btw. 
