It might depend on design of power supply. Some class D amps have straight linear PS while others (like mine) have switchers and some have switchers with power factor module. The most sensitive to power cable is perhaps linear power supply. Switching supply is less sensitive since it is regulated while Power Factor correcting type like Bel Canto Ref1000v2 have additional bank of capacitors minimizing short current spikes - a way that power supply normally takes energy from mains. All this is only my guess and I suspect that any amp can take advantage of better power cable. It is only to what extend.
Hifial is absolutely right - class D is analog. Outside it presents itself as as normal amplifier with about 1% of switching noise that is not audible but inside it operates on principle of Pulse Width Modulation (duty cycle of constant voltage square wave converted to average value of voltage). What is hard to understand is that duty cycle and not the voltage is analogous quantity (it is continuous without discrete steps)
Hifial is absolutely right - class D is analog. Outside it presents itself as as normal amplifier with about 1% of switching noise that is not audible but inside it operates on principle of Pulse Width Modulation (duty cycle of constant voltage square wave converted to average value of voltage). What is hard to understand is that duty cycle and not the voltage is analogous quantity (it is continuous without discrete steps)