Thank you very much for the nice and so detailed comment, Dave!
Indeed, this is something that I also see now, after your comment. All images are pretty much on the soft side, and I don't know if this is something good here.
And since also Paul mentioned that about a too centered layout I have now two points to be careful about when it comes to the next similar shots. I can see that a more off-center position would bring something more here.
Nice lighting on his hair and I get the sense of his movements, Nick! All in this series are a little on the soft side, maybe it's the scanning that does it, and I've noticed that Sammy is in the center of most of the shots. Possibly if he was placed off to the side more, it would make the composition more dynamic. They are all good child portraits, though. Dave.