I have to agree StreetD and Budrew. The Opus is a fantantic sounding player. I've also owned the Ayre CX-7 and the Cary 306/200. IMO the Opus is better. Also, I run the player straight to amps, which I know you cannot do with the MF. And, the Opus will act as a DAC for other components. Not sure the MF has that ability. I have not heard the Nuvista though, so I'll quit raving about the Opus for your sake since you're more interested in a comparison.
By the way, Budrew, what cable did you use to replace the factory supplied DIN cable?
Thanks-Sammie