When used with the Lumin A1, the Melco N1A (which replaced the Synology NAS) brought a quieter, more relaxed presentation to the sound. The sound stage was bigger and, generally, more airy. I was quite skeptical at first but the proof is in the sound!
Since it has a USB output, it can also be used as a USB server. Compared to the SPDIF output from the Lumin A1, fresh out from the box and using generic USB cables, sound from the USB output is almost as good as the SPDIF output from the Lumin.
The sound from the Lumin is more detailed and defined, tighter in the bass but does not flow as well as the USB output from the N1A. The sound from the USB output mirrors the LAN output - the soundstage was bigger and, generally, more airy. Smoother and less grainy. All relative, of course. When I tried the Ansuz A USB cable with the Melco N1A, the sound was better still with, for example, the texture on snare drums being more discernible, and a more immediate and dynamic sound.
Once MinimServer is installed (in place of the default Twonky), the Lumin and Kinsky apps can be used. Very useful though I have yet to find a way to save playlists.
I would think that the N1ZH (with HDDs) would be the sweet spot of the range, with the better and more solidly built casing of the N1Z series but without the exorbitant cost of the SSDs in the N1ZA. Plus, the N1ZH has dual power supplies (compared to single power supply the N1A), which are supposedly "medical grade". If only they could sub-contract the design and manufacture of the case to Aurender, that would be fantastic! Wishful thinking though...