I am speaking as a long time addict of naim separates and Naim DAC, and a current Devialet 200 owner, the two approaches are diametrically opposed.
With Naim you should be prepared to be forever climbing up the upgrade ladder with multiple boxes, and still feel somehow shortchanged glancing up the Naim upgrade hierarchy.
With Devialet the general consensus is all three model sound pretty similar except for power outputs. And there is really not much point in adding equipment. At the minimum all you need is a networked computer as source.
One of strengths though of the Devialet is of course the ability to add pretty much any source you want, be it a turntable or pretty much any digital or analogue sources
In fact adding a Hugo DAC and hook it back up to the Devialet A to D would be kind of a pointless and potentially lossy exercise.
Often times I miss the heady days of spending $ to upgrade in the Naim days. But then the Devialet's recent free firmware upgrade kind of quenches the thirst, without adding a cent.
To satisfy my upgrade my upgrade urge, I am thinking of adding a DDC like the Audiophilleo or a Weiss INT204. But even those I suspect are just necessary toys.
Different strokes for different folks i guess. Sound wise they cannot be more different, both are lots of fun.