Bipolar PSU verus battery powered voltage dividers revisited

[Ice-9]

I've just been working with some op-amp circuits i breadboarded some time ago. When i originally made these up i was using a 9v battery with a voltage divider network to power the circuit, now as everyone knows this gives 0v / 4.5v / 9v. effectively supplying a virtual bipolar power supply for the circuit which we can look on as being -4.5v / 0v / +4.5v.

This time, experimenting with my op-amp circuits I am using a bipolar psu that i have made that is powered from an AC mains adapter and is rectified with diodes and regulated with 7815 and 7915's. giving -15v / 0v / +15v.

The thing is that if i constructed the pedal using the voltage divider network all the jack grounds and enclosure shielding would be connected to the real 0v. ie 0v/+4.5/+9v (which is really the negative rail not gnd) but if i build the circuit using the bipolar then all these connections would go to gnd (real 0v) ie -15v /gnd or 0v / +15v

Both these methods obviously work but as we end up with shielding and grounds that are at different potentials when we connect a few pedals together, are we totally relying on DC decoupling capacitors that are on the input and output of each effect from causing noise problems ?

[Ice-9]

No takers for opinions ?