The Musical Fidelity A3 24 is very marginally better, and personally I liked the MF better overall compared to the Bel Canto, Chord and MSB dacs, fwiw. I sold the MF dac when I bought the Marants SA-14 as I felt I needed 100 more cd/sacds more then I needed a minor, though apparent, improvement in redbook playback (I can give specifics if you like). If you have the loot for a top notch dac, sure, you can surpass the redbook of the Marantz. The SA-14 makes for a great transport as well.
However, before adding a dac I'd spend time with isolation devices, power cables and interconnects. This is a very tweaky player, especially in terms of isolation, which will change it's character dramatically, more so then the addition of any of the above mentioned dacs ever would.
However, before adding a dac I'd spend time with isolation devices, power cables and interconnects. This is a very tweaky player, especially in terms of isolation, which will change it's character dramatically, more so then the addition of any of the above mentioned dacs ever would.