It was very much hen party screaming when I saw it in Edinburgh. This obviously led to a great atmosphere for the final scene, but the shouting and heckling during some of the quieter moments was very distracting. That said, I did enjoy the play overall, despite the appalling behaviour of a few individuals in the audience.
I have found that some websites (especially ATG) no longer allow even leaving 3 seats, often making it nigh on impossible to select good seats no matter whether you are booking a single seat or a group.