So, I don't know that I'm qualified to critique anything, but I'll give you my thoughts. I love the subject, very classical. I love the composition and the colors. The face is so expressive which really creates an emotional connection to the subject, which is the most important thing to me.
Technically, It seems traditional, but there are parts that stand out to me as a little off. The bottom of the beard for example or the little squiggles in the hat. It almost feels like there were places where you just applied a varnish impasto effect over a flat/digital brush effect, and it doesn't really feel like oil. There are places where this is not true, and they are beautiful (the background, the majority of the beard, and face).
In any case, this is the same effect I've been working on lately, so I love seeing what a real artist can do. As always, thank you for sharing your work with us.