Nice toning and a terrific expression of concentration. Perhaps a slight curves adjustment would improve the overall contrast, but not absolutely necessary. Well seen and well captured.
Nice portrait shot. Only thing that kept me from bumping it a little higher is that the back of his head blends in too much with the lights. Would have liked to see it "pop" a little more. Really like the composition.
I like the detail/tonal range you captured. Also, the reflection in the sunglasses puts a nice stamp to this photo. Not crazy about the composition but it works. Gets an 8. Good luck!