My experience adding the G-0s clock to the P-03U/D-03 combo is that everything quite simply got much better; imaging, instrument placement, musicality, achievement of 'truth AND beauty', etc.....
I was not really aware of how much of a difference it made
(over the option of clocking the P-03U to the clock in the
D-03) until after burn-in, I removed the clock and played the
same tracks again.
Suffice it to say, the G-0s is in my setup to stay!