Just for the sake of balance, I used one and hated it! I put it on within 45mins of labour starting, so very early as they recommend and I could just never get comfy with it. I didn't like it on my back, I didn't like the sensation of it (once I accidently bumped it up too high and it hurt when I pressed the button at the start of a contraction), I didn't like having to think about when a contraction was coming, and pushing the button and all that mental stuff when I was trying to just "be" and deal with it all. I MUCH preferred being in a warm shower- worked really well for me.

I wont bother with one again as it didn't work for me BUT I would have it again for my first labour without a doubt. It gave me the option of something that MAY have worked for me and my sister had used one with fantastic success for her so I think if it works for you then it was worth having. Another thing in your bag of tricks is never a bad thing.