18/6 or 24/7?

Used to be "lights on" for 24/7, now it seems 18/6 is in now. Does it make much difference in terms of growth?

Deleted Answer since the Question was changed..........................

Do what Mother Nature does in the Spring and Summer ... 18/6.

Vi

18/6 replicates nature better and also saves you 6 hours of power consumption per day

I believe the dark cycle helps promote root development. Plus, I think that when you do decide to switch into flowering and change over the 12/12, it will not be such a large jump for the plant. It will be enough to push the plant into flower, but not enough to stress it out.