I still find Hogan's book quite useful. Even when I "thought" I knew everything in it, I discover something to go back and check and recheck. As you learn more about your swing, try different things, practice, the illustrations and text in the book become almost "new material" as you find something in it that you didn't quite grasp in the same way. Its a never ending process. It seems as though no matter what "new" thing I try, or a "tip" I practice, I am always drawn back to the book. Even the so-called modern golf swing(s) have as their fundamental basis, the properties described in the book. There may be a few subtle differences, but the base fundamentals hold true. I've gotten a lot of "a ha" moments when I go back and read multiple times.