The new Lumin U2 seems to be using the same streamer as in the Lumin X1. That streamer is pretty amazing. The settings that you have access to is incredible. I use it for both analog duty and to stream digital to my PeachTree GAN1 via SPDIF (along with amazing volume control).
I also have Fibre Optic into the streamer and then SPDIF out. That Fibre Optic is essential in my setup (noisy). One reason I will not touch any Ethernet streamer built into a DAC.
The Sonore OpticalRendu is also incredible and is now discontinued until late summer when the new version comes out. The old OpticalRendu sounds more buttoned up compared to the wild child sound of the Lumin X1. Weird way to describe it but once you hear them side-by-side it makes sense. I love the sound of both streamers.