I can't recommend it highly enough. Mine was very similar to @Rodent01 's experience - 2 hours in the pool, knelt on all fours holding on to side, and just gas and air for the last 40 mins or so. I had a first degree tear, no stitching.
I keep telling everyone how unbelievable it was! The moment I went in the warm water instantly soothed and calmed me. I felt comfortable to go in 'the zone' - it was just a quiet room, the pool, the midwife and my husband. It was the opposite of my first labour, which was excruciating (he was back to back I think), in a shared ward, with a drip that didn't work plus an epidural.
Agree with above though, don't have your heart set on it as pools are limited and you never know how your labour will go - there are many scenarios where a pool will not be suitable. E.g. you can't go in if you have to be hooked up to the monitor or if baby's heart rate slows. In my case the midwife came and put a basic listening device on me every 20 mins or so to check the baby's heartbeat was all fine, and pretty much just sat in the corner the rest of the time to leave me to it.
Oh, also - I was very nervous reading about all the 'poo fishing' stories, and in the end you do end up naked in a pool with bits of red pink and brown bits floating about... it is NOT pretty, but you get out pretty quick!