While the figures may meet bench tests, I'd suspect more than 70% that in a listening environment (just adding). Personally, I'd rather use dedicated monos instead of mod (cause no two channels even on high end Hifi have 'zero' conflict, and pure addition.
Click & Pop free ? Well, not quite...
I observed Mains and Noise Floor variations 'relative' to power sources and /or other interferences. Isolated , until about 70% volume (2 o'clock pos.), It seems to do just what it's meant to. Clean input = Clean Output. Noisy input = Noisy (amplified Output). 20khz roll-off seems negotiable...