Turtle, et al - I had a doula and I would definitely have her again/recommend the experience.
I only decided on the day I went into labour that I wanted her at the birth (had hired her for after baby arrived). It was the best decision I made. DH was skeptical about having her at the birth, but now would be the first person to recommend a doula.
Although my actual labour/delivery was far from ideal and did not resemble what I wanted in the slightest, it was still a calm and controlled experience. I'm certain it was a thousand times better than it could have been b/c of her. In fact, given what happened (emergency c-section b/c of placental abruption) thank God we had her there. Never once did I worry about DH b/c I knew he would have someone to support him and tell him what was happening.
She was an amazing presence. Just having her there gave me the confidence to press for answers to my questions and to make sure I had as much control as possible. She was also a good buffer between the student midwife (fantastic) and the senior midwife (scary/hard ass) so I didn't have to stress about that situation.
OH, and don't get me started on how amazing she was once we got home! Cakes, freshly baked bread, every scrap of laundry was done. I loved every second she was here.
Long winded, but I really wanted to give you all an idea of how valuable a doula can be.
Oh, and to answer your question Turtle, she is also a hypnotherapist and trained in aromatherapy, too, so maybe think about the latter.