In Pure Direct Mode without any kind of EQ/DSP and using the exact volume, they would sound equally great.
In terms of measurements, I don’t think anyone has measured the AVM90, but the AVM70 has a SINAD of 99dB (THD+N 0.001%).
The Marantz AV10 has a SINAD of 106dB to 108dB (THD+N 0.0003%).
So both have great measurements and both will sound equally great.
I would compare other things like features, bugs, customer support, etc.