I've added a longish section to the systematics paper, S2.3, that deals with the referee's demands regarding noise model discussion. I think it's too long, but I'd like to hear comments, especially from John and Clem. Some of this can go in the private response instead of the paper itself.

http://bicep0.caltech.edu/~bicep2/papers/2013_systematics/

(see syst_rev2.pdf)