For my personal taste i would harvest, but i like the weed to hit like drunk driver on friday night, unexpectadly and killing everything it comes across, like brain cells, logic, understanding of reality...
But that's me, i like to feel like i just stepped inside the mad house, but some people like a more sedating high and would leave it for 2 more weeks, for my personal taste it would be a late harvest already as i am into what people would call 100% sativa but honestly its just premature thc, it hits differently and leaved you with energy to go and live life without any chance for couch lock.
(Just giving my personal opinion, if you like couch lock, defenitly leave for 1 and a half or 2 more weeks.