ARC 100.2 vs Pass Alephs

Has anyone compared these amps in a high resolution system such as electrostatics? I have a Pass Aleph V and cannot imagine a more transparent and natural amp, but it is somewhat power limited. I listen to all kinds of music through multiple sources. Are there suggestions re: upstream components and cables? Does the 100.2 sound better in a S/E mode or in a true balanced system?