All of the "best" bulbs are enhanced spectrum - adding more red to MH lights, and the enhanced HPS lights add more blue. Its growing obvious that both spectrums are the best choice for the plant. The light cycle itself triggers the flowering phase, not the spectrum of the light.

I'd like to see some studies that show that plants respond to HPS more than MH when flowering. I know its "a known fact" but then again so are hotspots from foil - but show me someone you actually know that has experienced it (burns from a wrinkle in the cabinet liner). Some of the old school growers I know only use MH lights, and produce some incredible nugs.