I have the MainzD8 - Ceramic power cords and speaker cables. The MainzD8 is something special. It is highly recommended with Ansuz power cords. Because the design focuses on the grounding of the system. The day I got the MainzD8 I also got the Aavik U300. I plugged the U300 directly into the wall. Then I added the MainzD8 to the wall with nothing plugged into it. What a difference. The background got quite a bit blacker. Then I added the U300 to the MainzD8. Background got a lot blacker. Better detail and more natural sounding. What I haven't tried is other power cords. The design uses a 10mm ground with smaller hot and neutral wires criss crossed in a way the it cuts back the capacitance and inductance. I got the speaker cables a few months later.
That said I've only had demos of the Ceramic and Diamond cables. Yes the Diamonds are even better but very pricey. Also a 4M power cord sounds better than a 2M. Don't know why but it does. The Ansuz X cables are supposed to also be very good but I haven't heard them. BTW these are from the designer of the Nordost Odin. The only downside is the cables are pretty ugly.
That said I've only had demos of the Ceramic and Diamond cables. Yes the Diamonds are even better but very pricey. Also a 4M power cord sounds better than a 2M. Don't know why but it does. The Ansuz X cables are supposed to also be very good but I haven't heard them. BTW these are from the designer of the Nordost Odin. The only downside is the cables are pretty ugly.