There are confirmed reports of people getting 1gr per watt of available light using the instant 12/12 photoperiod. These people are foregoing the vegetative stage altogether, and getting amazing results in just a few months or less. The only stipulation: you need to be well versed in a great flowering nutrient regimen, since you'll practically be using it right from the start. But...you also need to be able to supplement nitrogen to a plant that, in essence, doesn't need as much nitrogen as a vegging plant would. Add too much, and you're possibly going to end up with a final product that tastes overly "green"...or, worse yet, burning your plants with too much fertilizer.

I'm going to try the instant 12/12 method with some decent bagseed that I've been holding on to. (Not using my killer stock...just in case I goof it all up.) I'll probably make a grow-log here when I decide to give it a try.