OP -- Since you already made a decision, it's somewhat of a moot point, but I thought I'd share my experience with you anyways. Last year, I compared an Innuos Zen Mini MK3 with my Bluesound Node 2i, and really couldn't tell much of a difference. I was told that to make the Zen Mini reach its full potential I had to invest another $600 in their power supply. I then auditioned a Sonore Optical Rendu, and thought it was quite a bit better than both the Node 2i and the Zen Mini. The biggest difference was a reduced noise floor that let me hear more details and offered a blacker ground which I really loved. It also felt it was a bit less 'digital' than the other two. I ended up buying it of course.
A few weeks ago, I was looking for another streamer for my second system. A good friend of mine let me borrow his Lumin U1 Mini so we got to compare it with the opticalRendu in my system. It's a great unit, but we both agreed that the opticalRendu was slightly better. Again, the most noticeable difference was the lower noise floor. I hope you've bought your U1 Mini configured with an external power supply. Good luck and enjoy the music!
