I did the rush on a Saturday. Got there around 7:00 and was third in line. You can easily get there a little later, and still get good seats. There was probably about 30 people in line by the time the box office opened at 10, and I'm almost positive everyone got seats (for either the matinee or evening show).
Seats are in the front two rows. $32 a piece.
I know there's been a lot of negative comments about the show on these boards, but I really enjoyed it. Very, very similar to Truman Capote's novella, as opposed to the movie.