Man, this one has been argued a million times. Both sides present valid points/facts. I personally use 24/0 under flou's, and believe it reduces stretch and grows the quickest plant to maturity. But usually switch to 18/6 under HID to give the light/ballast a cooling break.
But I also can't help but feel, that it goes against natural genetic evolution, possibly ....not maximizing quality. I remember reading an article sometime back, by DJ Short I think, on environmental influence and induceing sativa tendencies to maximize potency. He got into hours in both veg and flowr, spectrums, even angles of light to, what he believed, enhance the turpine production and quality.
I'll look for it. It was an interesting read.