Here is some more anecdotal evidence
imho, each strain is different and needs to be tested with a first grow to get the harvest time really dialled in (after this, you use clones).
With that in mind, Sativa dominant should be run for 12 weeks first grow (longer for a 'pure' Sativa). And 10 weeks for an Indica.
Staggering the first harvest (over a week or more) will also help you to taste/feel any changes in the expression of the high, flavour and smell in the time (helping you gauge things for later harvests, using clones).
btw, I came to those harvest numbers after learning (first hand) the old growers adage:
If you think they are ready to harvest ..wait, at least one more week
Pistil hairs (colour/stages)
For me, all have basically turned red, shrunk back and matted to the bud (with only a few new hairs poking out over the whole bud). If I see lots of white hairs still (irrespective of the number of reds) I wait longer. I want to see pistil production dropping heavily, before I harvest.
Tricone colours
I grow more Sativa dominant (but this may be true of Indica dominant too), I learnt to never view the resin glands as simply clear, milky and amber (just three stages).
At least for the strains I grow, there are: Clear, Clear/Milky, Milky, Milky/small dot of amber inside, Amber red, Amber brown, Amber black.
Amber brown and Amber black are the real 'sleepy sleepy' part of the high (for my strains anyway), so I avoid them as much as possible.
For a balanced high and good flavour, I harvest when there are: Milky, Milky/small dot of amber inside, Amber red, some Amber brown (there will be a few Clears too)
This 'usually' corispodes with the flower times I mentioned originally.
Peace.
*Edit*
I should have added: I start counting flower days from the first day I see white pistils. Thats normally, about 7 days after the flip to 12/12