Mike, I find James Finegan to be a master of tact. He will rarely say anything negative about a course, but if he isn't comfortable praising a course about a certain aspect, he'll let other's make a statement. E.g., in his report about Bundoran GC in Ireland, he lets Christy O'Conner proclaim (paraphrased) "A man needs no more golf than Bundoran". Unless he's riding in back of somebody's BMW and has been told the cost of the vehicle. (That is a very esoteric old GCA post - can't remember who said it - that comes up the synaptic melting pot.)
How about a comparison to Bandon Crossings. Perhaps a better match?
I wish I could do that for you Daryl, but I haven't played The Dukes. I will state that Bandon Crossings has complex greens, no tree corridors, is built on sandy soil, and is affordable, but I can't compare it to Dukes except that, visually, the bunkers at BXings are not as extravagant. Oh, and I can play BX without jet lag.
As far as the soils of Dukes, I found only in Robert Price's book, that it is built on "Undulating Terrain". I found nothing on the composition.