Kevin - I have a limited education on each of the architects mentioned here - I've only played 2 courses by C&C and I've only played 3 by Doak (4 if you count Sheep Ranch and that number will be 5 next year when I get back to Bandon to see Old Mac.)
I'll jump in and offer thoughts on Pacific Dunes, Sand Hills, and Ballyneal, which are the three I've played that would warrant extensive travel and study in my opinion. These three courses are all in my personal top 5 (fair amount of US travel golf, but haven't played overseas yet.)
I have them shuffled a bit differently than Jeff. I prefer Pacific Dunes to the other two, but let me state we are splitting hairs by trying to rank all three which are fabulous. Pacific Dunes is probably helped by the fact that it was the first course I ever played that COMPLETELY blew me out of the water (I played the other two years later.) I am also much more familiar with the course after three return visits and multiple plays each time. All in all, I've played the course 9 full times with my own ball, 1 time alternate shot, and 1 time just sort of walking around the property in the evening hitting a ball when I felt like it. I can't add much additional commentary to what has already been stated on the Fan's Photo Tribute to Pacific Dunes thread.
As for Sand Hills and Ballyneal, I could probably go back and forth and be swayed either way on my favorite here, but for the past year or so I've leaned toward Ballyneal. I think Ballyneal has the better set of par 3s. Sand Hills wins on the par 5s in my mind, but only by a touch and only because Sand Hills has 3 of the greatest par 5s in the planet. In my mind, the par 3s at Ballyneal put more distance between themselves and the ones at Sand Hills - only the 17th at Sand Hills is in the league with those at Ballyneal in my opinion. The par 4s at both courses are outstanding, but I'll take the short 7th at Ballyneal over either the 7th or 8th at Sand Hills. Sand Hills is more breathtaking when you first see the course because the entire thing is in view, down below from the point you cross over the ridge. Ballyneal on the other hand reveals itself in pieces, so it appears less magnificent as a whole but the individual holes keep thrilling.
I don't view Sand Hills as the original and Ballyneal a duplicate or a wannabe. The terrain is similar in ways and different in others and the courses are very different. Calling Ballyneal a duplicate is sort of like calling every links course in Scotland a duplicate. If anything, I think it is the business model more than the course which is a duplicate. Mr. O'Neal might not have ever taken the plunge if Sand Hills had not proved to be a success. Let's all thank our lucky stars he moved forward and contacted Mr. Doak to do the work. C&C and Doak both used the given terrain to its fullest, and whichever you'd prefer you'd be better offer playing both of them than 99% of the golf courses in this country.
Those are just some more early morning Saturday thoughts, so take them for what you will.