I haven't replayed many courses which had serious work. Probably the few which stand out to me are Pinehurst 2, Old Town, Pine Needles, Mid Pines and Stoneham. I would say that none of these courses had any real architectural bones changed. Still, the work at P2 was completely transformative. Removing the rough created a course which is far more compelling off the tee. I know folks were handing out 10s for the course previous to C&C stepping on the property, but to me what was made of that Bermuda wreck is so much better that I am convinced the big wigs got their ratings dead wrong. That is unless the scale goes above 10 in rare circumstances.
I think my point is the marriage of design, presentation and maintenance is so closely related that to parse about what is what is pointless. If any of the three elements is not in step, a course can easily go from great to good. That said, I think P2 is the only course I recall which so completely changed that it made a huge difference in quality. Ya know what, I think the same thing could be done for TOC.
Happy Hockey