Power supply upgrade for Audio Note UK Preamps??

Has any of my audiophile friends heard the upper level Audio Note M-6 or M-8 preamps with the power supply upgrade now available? I have heard the M-8 with the older conventional power supply and it sounded great. Just wondering whether anyone has owned an M-6 or M-8 and upgraded the PS or traded for a new unit.

Thank you for any insights

I have a new M8 with the new power supply and previously had the older one. The new M8 is at least 50% better...no kidding. It is really something.
Audiobrian, you might want to contact Nick Gowan at True Sounds he is the US service center for Audio Note UK. Nick knows a great deal about upgrades/modifications to Audio Note gear can improve on the design. Nick owns an Ongaku and has even performed modifications to it.