My take is that chess is a fairly individual endeavor.
What works for one person does not necessarily work for another. And what works for one person for one phase of their development will not necessarily work for that person at other phases.
This is my problem with all the people saying, "Study tactics!", "No, study endgames!", "Don't study openings!", "No, read My System!", "No, play the Ruy and the QGD!", "No, read Silman!", "No, read Dvoretsky!", "No, play OTB!", "No, get a coach!", etc. etc.
This is not a one-shoe-fits-all situation.
I give players a certain amount of credit that if they pay attention to their results and make adjustments as needed, they will find ways to improve.
For me, The Encyclopedia of Chess Combinations put out by Informant was a big help. But honestly, no single tactics book has helped as much as good endgame books, game collections, or instructional books such as My System.