A quick vray render.
Looks great to me.
I think the only thing I'd add to him would be a bunch of small folds in the fabric. That might take too much away from the cartoony part of him though.
if you dont have zbrush,
give meshmixer a try(its free too) for the clothes(you can select them
and extract and extrude them as separate parts(add thickness)
cool character he could look better though with separate meshes for the clothes like i said.
so the shadows cast down right.
The render looks too smooth.
Mouth almost disappeared.
Welcome to the club. Matcap based renders aren't Raytracers.
So, have it in mind.
There will never be serious sculpting under such conditions.
Sculpting is about lighting. As Rodin and other great sculptors stated.