I am a big believer in everything matters, and Roon core machines and Streamers are no exception. Most salient points have been covered here, especially how USB connections mean the DAC handles the clocking and AES means the streamer handles the clocking.
I am a fan of a machine that is both Core and Streamer. To me , this puts core directly connected to the streamer, and special connections or optical isolation are not needed between the two. Additionally, it saves a component, space, power cable and connecting cable.
I have two such machines. The oldest, a Grimm MU1, can handle both Core and streaming elegantly. It outputs AES and not USB, and works beautifully with my Mola Mola Tambaqui. It formerly handled core for my main system as well, using an Auralic Aries. This is now in my second system, and Roon Core function has been replaced by the Pink Faun Scion, which runs core and streams USB to my Master Fidelity Nadac C and D (clock and DAC). As such I have disabled the Roon core function of my Grimm and use it as streamer only to the Tambaqui. This system now sounds better with the Scion running Core, so my findings differ with thoughts that core machines don't affect sound.
I have appreciated the sound improvements of every streamer upgrade I have made. Digital glare decreases and music is more relaxed and spacious. Listener fatigue decreases.
I also have improved my sound with stacked audiophile switches, and prefer this way to optical isolation.
As to the thought by @lanx0003,
I believe there’s a point of diminishing returns, and I haven’t yet determined where that price point lies.
I can't argue against that, but improvements are still to be had at every level.
Congrats on a nice system @tcutter!

