dCS Mosaic Vs Roon Nucleus Plus - Titan

I don’t have experience with Mosaic but I compared Roon to several native apps   While Roon is unbeatable when it comes to UI/UX, it falls short sonically in most cases when compared to streamer apps and proprietary processing. 

I also highly doubt there’s a sonic difference between Roon Nucleus models if you only use those as Roon Core without leveraging Roon DSP (that’s when processing power comes into play and you can benefit from an upper tier model).
To do Roon the right way I’d look into streamers that were also designed with a music server/Roon Core functionality in mind. Grimm MU1 is one example.

On my Nucleus Plus I first used an ifi Lan iSilencer which increased the performance but later replaced it with a SmoothLAN network filter which took it to another level   After breaking in detail, soundstage and clarity was at another level 

If you put all the right components in the chain ROON can still match the SQ.