My experiences with grandaddy purp seeds by ken estes were fantastic when the dude from DVG was doing the work with the plants. I grew 2 of the releases since that guy left and didn't find one good plant amongst 10-15 females, whereas previously I didn't find a single shitty female from the older seeds, I grew candyland twice from 2 diff packs, same with kens kush, GDP I only bought one pack of seeds and found 2 great phenotypes.I lost all to a bust which is why I grew the kens and candyland again from seed, I could not source GDP seeds in the old packs and wouldn't bother trying if I saw them in the later pack design based on my experiences with snowcap and another I forgot because it was so unmemorable.
I'd steer clear personally, unless ken has farmed the feminised seeds out to someone who knows what they're doing, because I heard after the DVG guy left he was making his seeds in the conservatory with multiple males in the room, so who knows what you're getting in terms of a cross. The plants speak for themselves from those later seeds and no-one is really talking about GDP/estes seeds anymore.