Well, speaking for myself anyway!
After hideous time delivering DD1 (45 hr labour, every drug I could get my hands on, failed ventouse and forcep delivery before 8 days in and out of hospital), I was in complete panic about DC2's birth and thought I would try the hypnotherapy route. Following a bit of reading up also thought water birth made sense...
Anyway, after listening to CD daily for 3 weeks, felt some twinges on Sunday night, by 2am they were 5 min apart but felt so mild... Stronger and less than 3 min apart by 3:30 when I went onto labour suite. Got the room with the bath (hospital policy says no to birth pools or water delivery but ok to labour in bath). I did ask for gas & air shortly before felt need to push and in fact midwife was brilliant and didn't even suggest I left the bath and daughter 2 born at 6:25.
Given that I had been terrified a month ago such an easy labour with only a graze which is 36 hours later (3rd degree tear previously) I still can't get my head around what a positive experience it was...
Sorry for really long post- still blissed out!