Hello @lalitk and all, As you know I also have the M12 Gold switch, and agree it is amazing, especially with the JCAT power supply. I also have the Muon Filter System x 2. (Two systems) I had them prior to the M12, and simply kept them inline after my switch which serves both of my systems. Tonight, I decide to evaluate my Makua with onboard Tambaqui system to see if the Muon still makes a difference with the M12. My wife and I Listened to Liberty about 6 times, with and without the Muon.
The answer was clear to us; the Muon still makes a noticeable improvement, even with the M12 Gold. And we each independently heard this. With the Muon, sound was richer, smoother, bigger, more air and space and just plain easier feeling. She described it as warmer feeling.
Now I too am anxious to hear the pro. Some lucky person will be acquiring my Muon! BTW, I do not feel the ER is still needed.