Which Rebbe

 

The שו"ת מהרש"ל: כ writes, the Chazal of --אינו דומה תפילת צדיק בן צדיק applies only to the תפילת צדיק for his own personal needs. However, תפילות for others then the opposite is true. It is more advantageous to have a צדיק בן רשע a בעל תשובה to Daven for you. According to the מהרש"ל, You should seek out a Rebbe that is NOT A  בנן של קדושים. His ברכות are more powerful than a Rebbe who is a  בנן של קדושים