There was a thread not too long ago which questioned whether GCA was losing sight of its roots and its mission - I think that right now it is demonstrating how relevant it is.
The threads about the US Open are clearly interesting and very informative - the course setup, how it played, the strategy needed to get around, etc. The thread about the poa annua is invaluable to a novice such as myself as it points out how it works so well, the quality of pushup greens, and links to articles which thoroughly discuss poa annua.
There are other threads about architecture that include a sometimes heated discussion about the design of Erin Hills. NGLA's 13 is being discussed along with TOC. #7 at Engineers is being discussed concerning the tree removal and its rebirth as a skyline green. And that's only a small portion of what's going on.
What a great website.