That Nick Nixon show is great, and seeing all of the Brown sisters together is quite something! Last I was there, there was room for one more print... I think they might add this years Brown sisters portrait before the show comes down. Think it's up until May. If you are in Boston or passing through in the next few months, it's worth seeing. I enjoyed the Avedon up to a point... it was all fashion work, none of his more interesting portraits. That show may have closed recently, I think. I need to get there to see the new wing...