if you could take a better close up pic you can get some good opinions from us,hard to tell from that shot.but it looks big and nice :)
what part of the world or how far into fall are you in might help also.usually when 95% of the pistols turn colors from white to red or orange its done .but I go by the trichome colors and look for about 25-30% amber.for my outdoor stuff I don't chop em down until they get at least 1 hard frost and the leaves start to turn colors and fall off.