Ronnie, as I'm sure you are aware, the 818v2 will down-sample to 88k at its USB input, so the comparison is, I guess, of Roon's down-sampling code and the 818's down-sampling code, plus the difference in the ID41 and USB pathways.

The 818v3 will, as Ludwig says, presumably maintain the 176k from the USB input internally within the 818 and send it intact to the 8kSEs using the "MQA mode" of MHR.

Roon Developer and ex-moderator of this Forum
I am #25 in the HH1 photo of fame.