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
I found it. Also, I forgot to mention that I have a Roon Nucleus. Will I still need it?
Hey Gary. Hard to put a number on it but the EtherREGEN is a solid upgrade for the 640 they are asking. But you can then spend another 1,000 on a LPS and a boutique Ethernet cable. Head over here:  Look for the Uptone sponsored forum   All the info you need and more. 
Have the 700 installed. Sounds pretty good out of the box. Will report after a few days. The app is a big upgrade but was hoping I could have all sources in a DMS playlist but looks like just local attached files . Would have been cool to have Tidal,Qobuz,USB and SD in one playlist. 
Benzman, Thanks for the info. I’ll look into it. Give your new 700 at least four days before you start any critical listening. Image focus and depth really locked in around day 4.  I've noticed additional improvements in detail and ambience up through day 12.  I can create playlists using Tidal, USB and NAS. When viewing the playlist page, icons for each source are in the bottom left corner of each album art. This is how I compare SQ of each source to each other. Same song from Tidal, USB and NAS. Makes it really convenient and fast.
I am about 220 hours in on my new 700. At 200 hours I noticed another layer of resolution, depth and clarity opening up. The one thing I have realized as a major difference between the 550 vs 700 is on lesser quality recoding's, not the digital resolution per say by the actual recoding itself. The increased resolving power of the 700 highlights and creates a high level of noticeability around the music's production flaws.   
I hear ya Joseph. They say that you listen more attentive to new equipment and maybe thats why there is a perceived improvement. You don't have to listen very hard with the 700. That's going from the 600, so from the 550 you must really be digging it.