When I first switched to Roon, I thought that an "Audiophile Grade" silent PC running Roon Bridge would be perfect between Roon Core and my DAC.
I then tried the UltraRendu from Sonore-SGC... what a difference ! Every aspect of it was better soundstage, tighter bass, smoother highs. So impressive for such a small device!
Last year I decided to go optical, and bought a OpticalRendu. Again, what a HUGE improvement, especially a much lower noise floor. Following Andrew's advices at SGC it was frankly easy to change from Ethernet to Optical, ans SO worth it.
My budget won't allow for the Signature Rendu, so I'm a bit jealous ;) but not too much, since the OpticalRendu is quite an amazing device.