New Cary DMS 700


 I have the 600 and it is a great piece. 

The 700 looks to be on the next level. Ladder dac

https://carydirect.com/shop-now/dms-700.html
128x128benzman
I have my best of the best on a 1tb SSD plugged in to the Cary. Other than more storage what would be the advantage of a Nas if I was only accessing from the Cary?
Cool feature
The DMS-700 has expanded the function of the 3 USB-A and SD Card Slot inputs to be accessible from a networked computer. This means when the DMS is powered on, any storage connected to the DMS will act as a NAS Drive (Network Attached Storage). This allows you to copy your music file directly onto the USB or SD Card from a network computer without needing to disconnect them. This simply turns any USB drive or SD Card connected to the DMS into a NAS drive. Playback from these drives can be direct (computer-less) or monitored and controlled from a computer-based server i.e., JRiver, Twonky, etc., or even via Roon. What’s more, if you have more than one DMS you can play files from one DMS to another
I have a Cary DMS-600 and I can connect fine to my Synology NAS.  Have you tried turning on the Media Server in your NAS?  The Cary can find the media server without logging in.  What's more, it doesn't have to index all the metadata again.  I did just try using the PC share only and I can access it while logging in as well.  I just put in the IP address of the NAS.  Logging in fine with a non admin account.
So on the 700 you can combine playlist from Qobuz , Tidal,USB, Network etc ?
that’s huge. 
Thanks everyone for all the information and suggestions.  I'm still working through my NAS issue and may switch to a local SSD soon if I can't get things working.  In the meantime I thought I would let you all know what I think about the 700.  Before buying the Cary I used an Altair (gen 1).  It sounded good but was fatiguing compared to my TT.  I have a Cary Xciter DAC in my retired equipment closet and just for the heck of it I decided to run the streaming output of the Altair into the Xciter DAC. Big difference!  More analog and enjoyable listening to my ears.  I believe the Xciter uses the same AK DAC family as the newer Cary streamers.  So that's what got me looking into the DMS-700.  Now onto the DMS-700.  When I first fired it up I noticed more detail and truer instrument tones.  Acoustic instruments sounded significantly more real.  Low end was more solid and balanced in the mix.  Timing was improved too.  It wasn't until the 4th day of ON time that I starting hearing acceptable image, focus and air.  I'm on day 7 of running in and the DMS-700 is now exceeding my previous digital system in all aspects.  It's also giving my class B analog equipment some competition too.  I'm really enjoying it.