NAD C658 DAC vs TEAC NT 505

"I am leaning toward a sweet tube sound" -- doubt you're going to get that from this NAD or Teac, tbh! Why not look at Metrum?

I am also considering the NT-505. I currently own a tube DAC (Musical Paradise MP-D2) with the AKM 4490 and love the warm sound but that is likely also due to the effects of the DAC's tubes.

One thing that surprised me in the NT-505 specs is it must be connected via a wired Ethernet connection for streaming music.  The controller app does work over WIFI but not music streaming. Curious if this is common with higher end DACs that play higher resolution music? To be honest, I would rather a DAC manufacturer not include WIFI when I can buy a quality network extender to plug into for much less than what the incremental cost would be if they provide WIFI capability.
The NAD C658 using the BlueOS controller is a big plus for me as I already have BlueOS in the house and am familiar with it. NAD is also fully WIFI streaming capable.

The Nad also has Dirac.. and BluOS of course

Looking at the NT-505 to replace my Bluesound Node Marantz HD-DAC1 combo.

Seems very capable, the Android and Apple based interface looks good, I suspect on par with BluOS, and it does DSD over USB.