A handsome fellow with good angle in frame, good shooting angle, like the little flipped up feather on the back. Nice water.
I might try a version with the duck just slightly brighter, perhaps a quarter of a stop, to try and bring out a little more detail in the darks without over doing the whites.
You could of course play around with dodging the darker areas, or some shadows work, or even fill light, to see if you can tease out a little more detail.
Framing perhaps a sliver tight below. I would trade a bit off the top for more below.
Joe, difficult character to expose, but you have done reasonably well, as there is a hint of purple and green visible at the back of his head. The eye also stands out well, and agree with Randy regarding the space top and bottom. Love the droplets.
That's a beauty, I agree with the comments re cropping. Also maybe just a tad more light in the darkest plumage. Love that bill and the plumage detail.
Joe, shooting angle and details are great. nice water texture as well. You should pull up the midtines, I think. When you protect that white patch in-camera, the midtones need adjustment in processing. that is what I pretty much always end up doing.