As the impedances of the PCB is so high, the advantage is actually quite small. You get the most benefit from grounded metal shields around the circuit; usually the chassis. If this can't be connected to signal ground, you may want to design a second floating shield inside.

The dimensions of the stitched side-to-side vias and areas can form resonant circuits or cause problems at rf frequencies.

For most audio frequency circuits , a pcb will cause no more hassle than hand wiring . High gain circuits can give fits. Sometimes the use of all grounds connecting back to a central point will eliminate loops . good ground planes can help eliminate problems , while bad ones can cause problems.

For audio work though , the capacitive reactance will be low to decrease your concern. inductive reactance of traces will likewise be negligible in effect . This is not to say that one can ignore good housekeeping practices . Theorily , any circuit with gain at or over unity can be made to whistle or suffer from deleterious effects accidentally , given enough bad engineering .