I do not have wide enough experience to answer your question but I will tell you what I can. I went from an $8K CD player to a Mojo Audio Mac mini server then to the Antipodes DX. I have had Antipodes upgrade the DX twice and then added an outboard end point so I run Ethernet directly to the DX and then Ethernet from the DX to the endpoint (currently the Metrum Ambre or SOtM triad since I own both) and then either USB (when using the SOtM endpoint) or AES/EBU or I2S (when using the Ambre) into my Metrum DAC. Switching from the internal Roon endpoint in the DX to the external endpoint (either Ambre or SOtM) was a bigger change IMO than going from Ambre to SOtM. This current set-up easily tops the $8K CD player and is the best front-end I have had (I do not use vinyl).
Removing my preamp and adding the Adagio DAC-direct actually made some difference in resolution, even though my other DAC is the very good Pavane L3. I want to try adding the preamp back in so I received instructions as to how to remove the volume control from the preamp circuit by installing two resistors - resulting in a unity gain buffer. Volume will be controlled by the Adagio while the SMc preamp will maybe add a little special sauce. I purchased two (expensive!) Audio Note 2W Silver Tantalum resistors to perform the bypass so I am excited to hear the result.
Removing my preamp and adding the Adagio DAC-direct actually made some difference in resolution, even though my other DAC is the very good Pavane L3. I want to try adding the preamp back in so I received instructions as to how to remove the volume control from the preamp circuit by installing two resistors - resulting in a unity gain buffer. Volume will be controlled by the Adagio while the SMc preamp will maybe add a little special sauce. I purchased two (expensive!) Audio Note 2W Silver Tantalum resistors to perform the bypass so I am excited to hear the result.