I've been growing Kens GDP for 6 years (several packs). Lots of breeding and pheno hunting. Lots of green phenos. Not much grape smell, more skunky. This year I grew a new breeder pack (10 seeds) and got 2 that showed a little purple on the sugar leaf tips (my other purple strains are full of color now). Don't get me wrong, I love this GDP, works great for me but I get a tolerance to it fairly quickly and have to switch to something else for a few days. I've grown so many and they never come out like the pictures they show. Buds are small but dense and they don't produce much even after 12 weeks in veg, some are super larfy and a pain to trim, some are almost leafless and need almost no trimming. They are not stable at all and it really comes down to finding 1 exceptional plant to make a keeper. I found an exceptional male (green) in the 2nd year, all his progeny are great even if not purple. I got 1 this year that should be better (purple and great smell in veg). Will have to grow out his seeds to test him before I let him de-throne my other male.
Next year, I have The Purps and Blimburn GDP in the line-up. Want to see if they're any better. If anyone knows where to get the best (stable) GDP, I'd love to know too!