Ron,
The lens may or may not be great, but for sure I like the photograph. When ever one gets to see just part of something it provides an extra boost of interest to the picture and in this case gives movement. I'd work on that eye to try to make the front of it with the light point sharp and the back part less so. Just experiment with that and see if possibly the fish movement increases.
To know if the lens is better than your other lenses we'd need matched images. However, I do like this picture and it's a step forward.
Asher