It depends what you want your high to be like. What strain is it in the first place?
If you want a cerebral high then you should harvest earlier, when the trichomes are cloudy. If you want a heavier body/couchlock stone then you should harvest when the trichomes are slightly amber. This is because some of the THC is starting to metabolise into CBD and other cannibinoids, that provide the heavier stony feeling. It all depends what you want. Nice looking plants. But as JP1 said, the highest THC levels are when the trichs are milky!