This is an interesting question. I read through the posts quickly but I think that Chris Kane said a lot in his first post.
It would be so hard to really answer a question like this, at least from a pure (or original architectural) perspective because so many of the classic courses have changed so much over time. Some maybe for the better but most probably for the worst! (at least when it comes to their real original architecture).
But all that being said, my gut feeling would be, that the majority of the "Golden Age" courses would be inferior to the majority of the "Modern Age" courses. But that the best of the "Golden Age" courses would be superior to the best of the "Modern Age" courses, possibly in quantity but definitely in architectural quality.
There are a few remarks on the posts in this topic I think I might take a bit of issue with too. Someone said that some of the "Golden Age" courses went out of existence because they really weren't very good anyway. There might be examples of that but the reverse is probably far more true--that some of the very best of them went out of exsitence anyway.
The New York Met area is certainly the most shocking example. And Dan Wexler's book "The Missing Links" makes that abundantly clear. The reason in the NY Met area is probably just that so many of those really good old courses were built too close to the rapidly expanding population of one of the largest cities in the world. Some of the ones in close were very good because the money was there and convenience of distance was a big issue with the transportations or the time. The Lido alone and its demise probably proves this point, but there are so many others, ie, Timber Point. And the other primary reason is the next paragraph.
One only needs to take a look at the ravages of the depression era to understand many of these great courses falling by the wayside! Some of us understand that the depression era had some significance in the evolution of golf and golf architecture (particularly in America) but I don't know that one of us has a truly clear enough understanding, at this point. I mean the real impact it had on both the golf courses that preceded it (and some built in the beginning of it) as well as the many influences it (the depression era) had on what was to follow it, both in new construction and also the failure of almost everyone to understand the real distinctions and differences in the architecture of the two eras.
The hiatus of the depression era, and the duration of it alone, was of enormous impact in ways we find hard to imagine today, and so we really don't. One really only needs to look closely at the incremental aerials of any "Golden Age" course to start to understand! It's not just the differences you see on a particular course with aerials say from the 1920s to the 1990s, it's that if you look at enough of these courses and enough of their incremental aerials spaning these years you start of see that the corruptive evolution is so identical on all of them!
There was another remark, I think by Dan, about how the old courses were generally for fun and for the accomodation of all golfers, and that the newer courses were built harder and more challenging. Maybe that's not what Dan said, but if so I think that's something that should be looked at carefully.
It is very interesting to consider some of Tillinghast's thoughts on that as he writes an article taking J. H. Taylor to task for criticizing the new American direction in challenging design (very much "Golden Age", BTW). Also some of the thoughts of Crump and certainly the writings of William Flynn! And we should consider more in that vein the actual "design intent" of many of the best of the "Golden Age" courses and their architecture that were really not intended to accomodate every golfer. They were designed specifically to challenge the best--Shinnecock, Winged Foot, Bethpage, Pine Valley, Pinehurst, Oakmont, Augusta, Baltusrol, Huntingdon Valley, Merion, Lido, Yale, Shawnee-on-the-Delaware and even GCGC and NGLA in its time--and the list goes on and on!
Maybe I'm a little off on this because clearly the great ones that were designed to really challenge are far more noticeable for all the obvious reasons. The LuLus, Misquamicuts, Pipings, Creeks, Fishers, Yeamans, Pasatiempos, Myopias even the Seminoles probably a bit less so!