Based on the preface, what qualities seem to define a major, impactful Guru biography, and how does Shri Sai Satcharita fit this description?

The preface in Chapter 0 implies that a major Guru biography is one that is detailed, widely known, and used for devotional study like Parayan. For instance, the Brihat Guru Charitra is cited as a prime example, being famous and studied daily. In contrast, other works are noted for being too short, like those by Dasganu Maharaj, or not yet famous, like the one by Tembhe Swami. The Shri Sai Satcharita, written by Annasaheb Dabholkar, is positioned as the modern equivalent to the Brihat Guru Charitra. It is described as a recent, sweet, inspirational, and grace-filled biography of a "crown jewel of saints," and the preface states that no third work written in such detail can be found.