Pretty darn good I'd say!
Only because you asked for critiques I'll mention a few nitpicks. The cigarette looks a little too yellow to me, I would put in more orange and red. Something happened to his right eyebrow between the two renders. As a personal preference, I would like to seem some white in the eye to avoid looking like a demon or alien or whatever. The inside of the far side of the collar seems too black and there is some background showing through, is the inside of the collar missing? You might try softer lighting for the light source that is creating the shadow from the near side of the collar.
He is often portrayed with the eyes hidden by the brim of the hat, it might be fun to do a pose or camera angle like that. Just from a google image search (
https://www.google.ca/search?q=Jigen+fr ... 0&bih=1324 ), the beard might be a little more pointy around the chin, more forward and less down. The ears and nostrils are makehuman problems, the slight weirdness of the wrist is also makehuman I'm sure.
There seems to be two different style for the nose in the drawings, one quite small, the other long and very pointy, so no issue there.
Again, these are just the random thoughts that came to mind comparing him to the drawings from google, your artistic vision should be paramount, particularly where to fall on the spectrum between cartoon and photorealistic.