I've still got mixed feelings about it. I had some pretty good results, and I've had some results that didn't seem to show much of any benefit to it.... only one single bit that I didn't really care for out of that.
I have a couple hunks of Flank Steak that I sprinkled with Koji yesterday, I'll likely cook those up tomorrow afternoon. I can likely cook one on my pellet grill, no sous vide, one totally sous vide... and I have some other that haven't had koji on them, that I could do both ways as well....
I will say , that from what I've seen so far, I don't think Koji is some magical dust that can make a bad steak into a good one.
I have never actually aged my own beef, and have only ate high quality aged beef, probably once in my life, ( and it was good )... but in general, I personally never went into the Koji trials, with any notions that it would somehow replace aging of beef. Mostly , I went into it, with a strong curiosity, and like you, I've mostly come out not overly impressed, and happy that I was able to get to try it for myself.