My non-expert opinion:
If the input stage of the amp has good PSRR, minor advantages or disadvantages to a particular PS should be ignorable. I think the choice is probably better made by considering cost and pysical dimensions. What will better fit in your planned enclosure.
The only obvious disadvantage is the leakage current is increased for each parallel cap.
Whether this is relevant, or larger than when using a single large capacitor is dependant upon the capacitor choice, but it will increase quiescent current flows in the PSU wiring, which could have sonically degrading effects, particularly if leakage current has an AC content.
It's not a good idea to parallel large caps. Best if doing so to introduce a small series inductor into the rails to avoid a problem arising when the caps' internal inductance and capacitance combine to form a resonant circuit. This leaves "holes" in the power supply response which are readily audible.