I like the build quality of Aries Cerat better. I have liked the sound of systems with Aries Cerat DACs in them better than when I have heard the Lampizator. That said, I personally have never done a compare of the two in the same system.
Regarding server, when you see a device is "Roon Ready" like the Mola Mola it is a DAC and Renderer/Player when you connect to it via ethernet. This means that the renderer/player duties are not being handled by the Nucleus. This is optimal as this stage does not require a lot of processing power and noise can be introduced with too much processing power.
When you connect via USB, the Nucleus is performing as player and server. This is where it tends to underperform and sound mediocre. If you have a USB cable lying around, try connecting the Mola Mola to it via USB. I bet you will hear a significant degradation in sound quality vs your current ethernet setup.
The Nucleus is a stunning value when used as a server alone. Best upgrade from a Nucleus for people connected via USB is not to get a higher end single box server but to get a separate player renderer.
This is because even the best servers are not at their best when performing both tasks. It is just the nature of Roon to perform best when server/roon core are on a very high powered computer and the player is on a medium to low powered computer. This is why Antipodes adopted a dual computer approach and why Pink Faun recommends two units for absolute best performance.
