Two different products here ,the MF is SS and tyhe ARC tubed of cource.I haven't heard the MF but I do remember how people liked it for it's resolution.However I own the ARC DAC-3 and I am very pleased with the sound,silky highs and mids and very transparent,and I put it next to Sonic Frontiers SFD2 MK2,Northstar M192 and the Mark Levinson #35.A reminder that ARC has one of the best reputations in product repair and support if you ever need it,I know I sent mine to them for retubing a few years ago and came back spotless.I would buy the ARC DAC-3 if I were you.
Regards from Toronto.
George