I attended Active Birth classes but was unusual in my group in that I was planning a hospital birth and not a home birth (there's a very strong home birth unit where I live).
I was fairly sure I didn't want an epidural and like you Active Birth seemed to make a lot of sense, but not having given birth before I thought it best to keep an open mind until the event itself.
The classes were informative, very relaxing and I met some really nice people. A lot of the discussion concerned how to cope if you need intervention during labour and still feel in control. It taught me to believe in my body and know that my body was designed to give birth.
When the time came my ds was born very quickly (less than 4 hours from first twinge)and although I'd planned a hospital birth, I gave birth in my ds' own bedroom on all fours and I wasn't scared at all.
I was shocked at how strong the pain was, but more amazed at how well I could cope with it. If left to give birth in a confident and relaxed way your body will produce natural and extremely powerful pian killers of its own. Its almost as if you can somehow distance yourself from the pain a bit like its happening to someone else, whilst at the same time being totally aware of how painful it is (does that make any sense?)
I found a warm bath very helpful and my dh running a warm shower head over my back even more so. An ambulance crew arrived in the last half hour or so and I then had gas and air(Lovely, lovely stuff!)
I posted my full birth story here
I was very lucky to have had such a positive birthing experience. One things for sure, Its very rare that anyone gets the labour they planned, but I'm sure the Active Birth classes I went to would help anyone cope better with any labour.