I own the X1 since July 2018. I can say that this is a streamer that you can't only appreciate in terms of timbre and speed, but also for the image and soundstage. The aeration between instruments, the stereophony and the resolution make the listening session become more of an immersive experience. After at least 500 hours of break in and I'm getting more satisfied.
I strongly recommand to use the optical connectivity. Moreover, the optical connection can bridge the signal from the modem electrical circuit (on which a multitude of pollutants can be connected) to a dedicated electrical circuit. A big plus. A simple $100 Cisco switch and $12 adapter makes this possible.
I prefere the one box concept. First, the server inside is totally dedicated to one sigle task, wich is not the case with a computer that runinng multiple processes and services in the background. Second, the integration with the DAC is direct and well designed.