For example, if one starts with Prelude To Foundation as the entry point, the reveal of Eto Demerzel being R. Daneel Olivaw in disguise all loses its' punch, while if one reads the original Robot books first, it becomes an astounding reveal, a true "holy shit!" moment, on several levels, the delightful surprise of clearly seeing Asimov kneading together two separate series so intimately and right before your eyes, the narrative doubles in size and scope in the snap of a finger.
The power of that moment, that opportunity that Asimov seized, makes it worthwhile to follow Isaac's mind instead of the plot in chronological order.