MF Nu Vista M3 Power Unit Umbilical Cords Change?

Yes, I did. Had some made up by Sweetcome in Hong Kong. Also got a 20 amp power cord made. They specialise in MF power cables. I thought it was a considerable improvement, especially the Umbilical cables. The PC is worth the money but not as good as my much more expensive 20 amp ones.

Can you elaborate on what the improvements were?

Just about everything, bass tighter, better transient response. I haven't used the standard ones in such a long time I have forgotten what they sound like. I liked the amp in its stock form but the cables are a noticeable upgrade.