Mike,
That's not entirely true..when I installed a set of Lucas 38# injectors and a 73 mm C&L with the correct sample tube, the car would bogg on hard acceleration. I installed an adjustable regulator and raised the pressure a few pounds to 43.5, and the car ran great. It went from bogging to burning the tires. Even with the EEC's adaptive tuning abilities, it ran great for more than a year. Then it suddenly stuck at 50 psi one day and could have burnt my new engine up if we didn't catch it on the dyno.
I agree that making adjustments with an EEC tuner or a custom chip is the better way to go, but sometimes a little extra fuel pressure is helpful for fine tuning.
If your adding the regulator instead of getting larger injectors...that's another thing entirely, don't do it. You risk a top end lean out, because most fuel pumps can't maintain flow at higher than stock pressures.
David