I have used a Bluesound Node 2, Allo DigiOne (standard and signature version), Chromecast Audio, Intel NUC with Schiit Eitr and a Lumin D1 in the same setup and the U1 Mini combines the musicality of the D1 with the clean sound of the DigiOne signature. It has only been playing for a few hours but it really impressed me so far.
At work I have used a variety of streamers (aurender, Auralic, linn, Cambridge audio, to name a few) and the one brand that always works is Lumin. Not to say that the other brands are bad but more to point out that Lumin has a really good hardware/software combination with their streamers.