Great thread! I bought into the Roon ecosystem. But very happy to read all the alternatives to it, and successes and failures of it.
To add to the kudos ... What I find especially unique and invaluable are, its zone group linking & advanced DSP.
In my "high-end room" I have three devices, two Raspberry Pi and one a NanoPi NEO, driving three DACs (one a ApplePi RPi HAT, two use USB out to desktop DACs) to drive
a) my primary speakers with no time delay or DSP/EQ,
b) secondary front-side speakers with a 3.2ms delay to account for the closer position plus slight EQ to sweeten the Tannoy NFM sound, and
c) to drive a sub using a 5.03 ms time delay to account for the extremely close position to the couch (snuggled up right behind it to feel the rumble), and -heavy- use of Procedural DSP to combine left + right channels to make a mono channel, plus subsonic filter to control the woofer, plus low pass filter to send it only low bass signals (the two together making a band pass filter), plus EQ... to create and incredible enveloping synchronized sound coming from three different sets of speakers at my seating position...
And -then- I can group-in any one of three other systems around the house, with all of them using a DSP EQ specific to the needs of the speakers in that room ... and all get the music streamed to them with no time sync delay to the ears beyond that introduced by distance / the physical speed of sound. And if I wanted I could account for that too so that the sound from all of the rooms are synced to say the center of my house. And some of the systems are connected via wired LAN, but most via Wireless (N).
It all blows my mind!