Hi,

I use the G91A only for CD, DVD, TV, DVR and Radio as an analogue source. I have set the volume of the G91A on fixed. The analogue output of the G91A goes into the Prime.
The USB input of the Prime is connected to my MacMini which serves as a RoonServer and my MC200 serves as a back up for Roon and as a NAS for Roon. Sooloos works fine too.
And last but least: It sounds incredible good on my headphones as well as through my NAP 200 End-Amplifier into my Guru speakers. (much better than my previous stereo pair of DSP5000 24/96!!!)

It works for me, so I don't see any reason to opt for a 218 or 'something coming'.

P.S.: I have compared the sound of the G91A versus the Prime/PSU (i.e. working independently). And no what comes in as analogue on the Prime stays analogue in the Prime. The Prime/PSU combo is by far the better Pre-AMP (for Analogue and for USB Digital).

Meridian MC200, Naim NAP 200, NAD C658, Duelund DCA 16 GA Speaker Cable, SPEC RS901EX Real Sound Processor, Harbeth Compact 7 es-3, Roon Nucleus Plus, Schiit Wyrd, Audioquest NightHawk, Audioquest Dragonfly Red, Bowers & Wilkins Signature P9, Roon
Bluesound Powernode 2 i, Guru QM 10