Hey Bro as you know I just went through the "chop/no chop" decision a few weeks back. IMHO, after all the research I did as a noob/rook it came down to knowing my grow was ready. For me the hard part to pulling the trigger was the trich's not being quite amber enough, 90% cloudy with bending heads and 50% amber, 90% pistils brown but not withdrawn 100%, and time available to harvest properly.
The final decision was made by just simple observation of the plants overall demeanor. I can't explain it in detail or in anyway that may help you, but I just knew, they were telling me "hey you, were done", "we fought the good fight and were ready to rest". And in the final analysis you know your grow better than anyone and have done an excellent job overcoming the challenges.