While I didn't see this show, my partner who is happens to be pre-op male-to-female, did go see it this past weekend and completely raved about the show.
She said that the play itself was really good but it all came down to Simon Callow. She has never been completely satisfied with performances over the years of transgendered individuals..in fact the most recent one she thought came close to being completely believable was Tony Sheldon in Priscilla.
However, she found Callow to be so real and so genuine that it was almost like he wrote the play for himself or better yet, he had lived it.
Sadly I can't make it to see the show but I was very pleased she was so moved by Callow's work and the show.