I think both are fine , I used 18/6 in the first week but it was very slow so now its on 24/7 full time.

Grows faster, looks very healthy. Some say the buds will be more airy if grown 24/0 lighting , but not by much..

And it all depends on other factors aswell.

I grew photoperiods before on 24/0 veg period, and they were just fine poped 12/12 later for flowering.