It's a little small to get a good look at, but it appears to me as if the skin has been somewhat over-smoothed. While not related to your work in post, I'll add that your DoF is somewhat excessive, and while a nice image as-is, it would have been improved with a softer, less focused background.
Another thing that might be beneficial for future work might be to try to avoid to show much of his neck. You did a good job in avoiding the double chin or the lines in the neck. But, I think the neck just makes him look a little larger. If you were able to show less of the neck and more the face (maybe more profileish) that might help the photo.
I agree on the DOF, here is where using the 50mm 1.8 at maybe 3.5 or so would have been quite helpful in smoothing out the background and making the shot a bit less busy.
For ATX - DOF is the depth of the field. I would love to go into more detail, but others have done a much better job then I could. Please do a search on the search bar above, or google it. The answers there should be more clear than I could explain it.