I recall Tom Doak mentioning that one of the key elements of CGC is that you are putting on 18 original Seth Raynor greens. No rebuilding, no restoration, no shrinkage and expansion. And, of course, the greens are amazing.
Another thing about the comparison between Shoreacres and CGC seems to be that at Shoreacres, the great holes are not the template holes; the road hole isn't particularly severe, the redan is odd, the short is great, more for its placement than the green or bunkering, etc. etc. The great holes are originals that put the ravines to great use (11, 15, etc.). In contrast, at CGC, the great holes are the template holes for the most part. Very cool road hole with a wicked green, great double plateau with a wicked green, fantastic short with a wicked green, great punchbowl with a wicked green......