I would do a soil grow to compare. At this point you have nothing to lose. And you know how to finish.

If the buds smell good fresh when touched then they should end up that way. Wish I could say what it is. You sounds like you got your shit together. It just ain't happening in the end product.

Sorry just thought of a friend on Key-lation to remove crap from his blood and clean it. He said everything tasted like metal. He lost a good bit of weight.

Very strange this problem is.