Hi Richard, In olden days I had an ARC Ref 3.... I know I know, it is an older ARC reference preamplifier...
I replaced Ref 3 with the little Rowland Capri original because I found Capri to be much superior in most respects.... And eventually upgraded from Capri to Criterion (same audio circuit of Corus) because it was clearly superior to Capri.
Granted,Ref 6 is probably better than Ref 3, so a comparison with Corus might be interesting.
One other thing you might try with your system is to power both Corus and Aeris through the new Rowland ultra-capacitor PSU DC external power supply . Finally the creature is shipping... I have not tried PSU yet because my system is in storage, but indirect reports on PSU this far have been extremely positive.
Saluti, G.