Bel personally I would rather have pethidine than an epidural, only because my experience with epidural was it made me unable to move from the waist down, I couldn't push (thankfully my body did this for me) and I couldn't walk properly for a good few hours after the birth, plus I needed a catheter in which wasn't that pleasant. Having said that, though, I would rather have no drugs except for the gas. But, given a choice I would opt for pethidine first and only go for an epi if it was really necessary, like in an emergency.

It is good to keep an open mind before labour but I don't think it is good to just rely on your Ob and midwife to make all your decisions for you, usually they will go with your best interests but not always so it is good to be informed.