Shairport or direct connection?

[ethelthefrog]

I'm looking to connect my headless Mac mini to my DAC/Amp and control iTunes using the iOS Remote app. But I'm curious whether I am better to run USB straight to the DAC or use Shairport through the microRendu. Shairport can only handle downsampled files but has the benefit for running through the microRendu. On the other hand a direct connection lets me feed the DAC a full-res file. Any thoughts? 

 

BTW, I understand there are likely superior options than playing directly from iTunes (like ROON) - but I've found the convenience of combining my existing library with new music sourced through Apple Music gives me the convenience I need.