Partly hearsay here:
On 100 octane gas, I run around 21psi all the way to redline on my vf34. Someone else with a vf30 posted that he dropped down to around 19.5 at 7000.
However, tuning has a lot to do with that, and I didn't tune that car.
On top of that, most respectable tuners will tell you that there are no differences in performance.
YMMV, and have fun either way.