Bricasti M3 w/network card vs USB

Thanks for the great info. 
Not sure what to do. I have all these great DSD files And no way of getting them to the Bricasti . I am looking at a Melco N100 for 2k which will do the trick or maybe spend a couple of grand on improving my streaming setup ( have a EtherRegen w/SoTM cabling in place already) and forget about the files. 
Haven’t even heard whet DSD sounds like on the Bricasti. Can anybody comment on that? Of course it’s always about the recording but just wondering if it’s worth spending even bigger money 5-7k on a server/streamer that supports the music services. Would Qobuz and Tidal sound better thru a dedicated player than the network card?

Since I have upgraded to Townshend Fractal F1 speaker wires and the Iconoclast 4x4 Gen 2 XLR my rig is really sounding good. Just want to figure out the final piece. ( for now)

The DAC plays DSD files well and it is capable of max resolution through either USB or Ethernet.  This is again driven by that I2S connection.  I don't find DSD inherently better or worse than PCM except in the extremes.  You will hear a bit of a difference on DSD upscaling DACs like Playback and probably Meitner.  

There are two different approaches to these digital front ends. You can get a streamer like a Lumin U1 which handles everything, typically using proprietary software/firmware.  These are good options.  They are stable and reliability is typically driven by the strength of the software.  Lumin is supposed to be pretty good.  Some are better.  Some are worse.  

The alternate is server & player.  Here you have a computer of some sort; PC, Mac, Antipodes, Innuos, etc... that runs an OS and most of the time, third party software like Roon of Foobar.  Innuos and Pink Faun are exceptions.  I am sure there are others.  That computer can play both part, server and player but rarely is it great at both.  

The server function is often best executed by a high powered computer as it handles all the local files and a very volatile internet.  The player/renderer part is often best handle by a mid-powered device.  If you have too much processing power, it can introduce noise in the player stage.  This is especially the case with Roon.  Other software can be a lighter load from a server perspective (JRiver, Foobar) and don't need the same processing power.  

The network card in the Bricasti is just a "player or renderer."  It doesn't need a lot of power and that unit is optimized to interface with the M3, M1, M12, M21, etc...  It is basically an M5 but without the separate chassis.  You would think this would be mediocre.  It is not.  This card is really good but is at its best when fed from a good server.  

I have used everything from a Roon Nucleus to an Antipodes K50 and have compared it to other renderers and players at differing levels.  It can be beat but not for a couple thousand dollars.  My experience is Qobuz and Tidal through a good server into the network card will sound better than Qobuz and Tidal though a streamer or unit serving as both server and player.