Got mine used from a Head-Fier, it's a pre bad grounding fix model (I don't hear any 60hrz buzz for the record at all in any way). I'll do the mod and see if it makes a difference or not
I upgraded from my Magni 2u/Modi 2u. Mostly because I wanted to try balanced. Im not sure if I noticed the balanced or not, but it was a rather big upgrade either way. Way bigger than I expected to be honest. Same gap is say from my motherboard audio, to my Asus sound card, to my old Schiit Stack.
I've heard from others the Ether CXs pair VERY well with tubes. Which I could see with the slightly laid back super natural sound the Ethers have
I know nothing about the 789 other than the million glowing reviews.
Maybe pair it with a Geshelli balanced DAC.
Wish I could be more use in that regard, I live generally in the middle of nowhere, so unless I want to shell out my own money to buy some sources or I have to drive 8 hours to Calgary or 8 hours to Vancouver heh