I spent a while tonight cutting off any remaining rust-colored spot I could find. So far it is hitting two of my plants pretty hard and the third one just barely. The buds don't seem to be affected though, just the leaves. So that's good. I wish it were just the fan leaves, those are easy to cut off.. the sugar leaves that are intertwined with the buds are a pain.
So, I should be able to tell fairly easily over the next few days if the neem did the trick. If I continue to see spots appear, I'll do one more spray in 7 days and then tough it out till the end by chopping leaves as needed.
I'm still not sold that neem will fix this problem, but I don't think it could hurt. My prior grows had this problem too so next grow I'll use it 3-4 times starting a couple weeks before switching to 12/12 to see if I can prevent the problem.
Did week 5 Flower nutes tonight. The colas are fattening up and I'm starting to see some of the white hairs turn brownish here and there. I've never taken a grow all the way... if the colas are this fat at week 5, I can't imagine what another 4-5 weeks will do to them. Getting pretty excited
Some pictures: