I have run 18/6 for veg but now run 24/7. As far as vegging I see no dif. The reason I run 24/7 is because I work in the veg room at all dif hours of day and night. It seemed that turning the light on and off during the dark period kind of freaked the plants alittle and took longer to start seeing white hairs when put into flower.

I might be in there at any time just watching them grow if I can't sleep. LOL
Only because I can't watch the buds grow for 12 hours a day. Life's a bitch when you can't sit on the porch and watch the grass grow.