What makes the 'Shri Sai Satcharita' and the 'Guru Charitra' unique among saintly biographies in Maharashtra?

The preface in Chapter 0 states that if one looks in Maharashtra, there are very few ancient, detailed, poetic, and comprehensive works suitable for Parayans. The 'Guru Charitra' by Shri Saraswati Gangadhar and the 'Shri Sai Satcharita' by Annasaheb Dabholkar are presented as the two primary exceptions. They are described as famous, sweet, succulent, and grace-filled. The text explicitly states that apart from these two Guru biographies, no third work written in such detail is found, making them exceptionally important for devotees.