Opinions on Dacs...

I'd cross the Benchmark off your list as "a little warmer" is not likely in its skill set.  The increasing number of NOS R2R DACs may be to your liking as they retain detail yet can also have a hint of organic warmth.  The Metrum Amethyst includes a good bit of the technology from their acclaimed upper-tier DACs but at a lower price point and might be worth a good look.  Best of luck. 

https://www.ebay.com/itm/123026758084?ul_ref=http%253A%252F%252Frover.ebay.com%252Frover%252F1%252F7...

I use the PS Audio DL III in a second system. For USB I use a USB?SPDIF converter into the coax input.  PS Audio did produce a replacement for the DL III that has asynchronous USB. Forgot what they called it.

Mytek Brooklyn DAC+.