Your plants look great. I'd wait a while before harvest. I don't see ANY amber trichs and the pistils haven't receded into the calyx's as yet. I think you're a few weeks out.
I've got 4 GDP's and 2 cheese under two 315w CDL's. Today is day 30 of flower. Your GDP's look like they're only 3 weeks to a month at the very most ahead of mine, but then this is my first grow using CDL's. My GDP's said 70 day flower, but those breeder numbers are always low as a rule.
Good luck with your grow. It looks reallly nice.