Sunlight Vs Artificial Light

I'm curious on different people's opinion on artificial light vs sunlight. I've had great success growing my plants by a window (replacing the dark hours with fluorescent). A plant I have growing now gets 7-8 hours of INTENSE sunlight a day. about 2-3 hours of non directed sunlight, and about 4-5 hours of fluorescent lighting. right now its on a 15-8 cycle, its been growing for close to 3 weeks and i can notice significant differences everyday.
The lighting schedule i have is awkward, because I'm constantly changing the plants environment. However it saves having a higher energy bill.
I'll have pictures up SOON

www.ArtWanted.com/Ejmi3612

I stuck my light meter in the sunlight coming through my window today and the meter hand flipped to the max measurable light on the meter. My 600w MH on a digi ballast does not even do that, it flips to about 80% on the meter. I wish I could grow outdoors.