My overall impression of this painting when Abdi first emailed it to me was very positive. I love the warmth of it, I feel the spirit of the man really comes through.
I'm not a portrait artist, but having managed one for 6 years and now running Stroke of Genius for 6 years, I've viewed and worked with thousands of portraits and had to critique a lot of them. I'm told I have a good aesthetic sense for whatever that's worth.
Regarding comments about the hat, the portrait artist I managed, who was very successful, painted his faces very detailed and as he moved away from the face, the painting become more impressionistist. His believe was that this tends to put the focus more on the most important thing in the painting, which is the face. He gets about $30,000+ for a portrait.
I agree with Karin that it's hard to critique the features of this man without having seen him or a photo of him. And, even looking at it now, I don't get a sense of his neck being too narrow at all. In fact, I don't look at his face and get a sense of anything being off.
And, Abdi seems to have mastered one of the things many artist have a hard time ever getting right...edges.
My own personal preference, I think I would have either made the painting wider (too late for that) or take a little off on the top. But, I'm not sure that this is anything more than my own personal preference for certain proportions.
And, did you ever see Nelson Shank's painting of the woman with the chair "doohickie" coming out of the top of her head?

Take a look:
http://www.artrenewal.org/images/art...TweedleDee.jpg
Last I checked, Nelson gets $60,000 for a head and shoulders and has painted Pavorotti, Princess Diana, Margaret Thatcher (all from life).
Sorry guys, I don't normally get involved in critiques, but felt I had to speak my opinion on this one.