The almost solid white pistils make me think that you have a bit to go, but the plant is starting to get that "im almost done look", I try to see the whole plant as an indicator of when I harvest but the trichome method is my mainstay, I grow an old school Afghani strain that doesnt really go full amber on the trichs, so i wait till i see the yellowish tinge to the trichs on the calyxes themselves, and when the whole plant looks like she has done her work.