I'll also echo what others are saying re: the FFT trigger pack and polymer frames. I received my FFT kit from Todd from his last batch (May?) and had issues with the hammer dropping off the disconnector and onto the trigger. The groove in the polymer housing is too narrow and prevents the hammer from rotating freely. It's just enough static friction that when the weapon is charged, the hammer stays stuck on the disconnector. Mine was right on the edge that if I tapped or pressed the hammer, it would pop free and down onto the trigger.
I spoke to Todd about this and he was helpful overall. His thoughts were that the polymer housing have inconsistent tolerances and that sometimes his hammers won't work. Kinda of disappointing but having worked in molding shops, I would have to agree with him. He did offer me a full refund and was helpful through my conversation with him so full marks for CS. He recommended the A&S unit but I opted to purchase another OEM housing and roll the dice. As luck would have it, I received an older aluminum housing and the hammer has adequate clearance. I need to re-assembly the trigger pack to make sure everything works but so far it's looking promising. For anyone interested in this route, I got my trigger housing from Midwest Gun Works. No idea if I got lucky or if they're sitting on a pile of the aluminum units.