@rooze What did you end up going with?
I've found myself in the same boat. ~$6k used budget and I also owned a CT5 that I really liked and it paired superbly with the Luxman M800a, which I have incoming, when I heard the combo 12 years ago. So I was thinking ET7 S1/S2 would be a safe bet. But I've also enjoyed some of the newer McIntosh stuff, namely the MC452, so looking into the C2600 brought me here.