Gary:
Wow are those loaded questions.
Again I must point to the work of others... Geoff Shackelford did a recent book on Cypress that covers all of this in great detail - check it out. I can't possibly improve on his words and pictures there...
But for my short answers:
What is it that makes them great?
They are filled with strategic options and choices, the greens are in general fantastic, they have a beauty hard to match anywhere else...
Can such greatness be replicated elsewhere?
Not perfectly. But the architectural principles are used on many other of MacKenzie's courses. Hard to duplicate the incredible sand dunes, though.
Or... does the "exclusiveness" of the club and the ambience of the site somehow make these holes better?
That is the final piece that sets them apart from other courses, without a doubt - there is a definite mystique to Cypress. Discount that, as at least one unnamed expatriate regular poster in here tends to do, and who will certainly give me crap upon seeing this for being overawed, and they are still GREAT in my mind, each one of them... but they are surpassed elsewhere... although each of 9, 11, 12, 14 have very few peers... Of course why one should discount this remains silly to me, the mystique is palpable to all but the hardest of cynics.
Assuming these holes are as terrific as some people say, are there examples of similar routings/holes elsewhere?
Sure - throughout MacKenzie's body of work, and those who try to emulate him.
Read Geoff's book.