MSB vs dCS Bartok

the extra power supply for the discrete is really mandatory in my opinion. Any component in the chain, always always opt for the one that has the best power supply implementation. And this case if the Discrete, just assume you need both out of the gate regardless of budget, find the money and get it. 

MSB is interconnect sensitive and impedance sensitive. Look to your amp and pre amp. Make sure you run the MSB as a preamp in any troubleshooting before you cast final judgement on the sound of the dac.