Did flash all my S9 and working great since. Less power, less chip heat....however they sometimes make a low pitch noise because of thr fans running slower.
I would like to know more about this. When the S9i came out I thought I read about a few people who had tried to run the S9i firmware on an S9 and it was said not work. How many S9's have you done this to? Which firmware are you using exactly (S9i or S9j)? What method did you use to upgrade the firmware?