I had my dd there in October 2007. The mid-wives on delivery were lovely and I was well looked after. I had to be induced as my waters broke and 4 days later I still hadn't gone into labour. I decided early on to have an epidural and the MV was totally supportive and the anaesthetist came very quickly.
The ward staff were nice too but it was really hectic and I think they let me go home too soon before bf was properly established and dd lost a lot of weight. I felt that after an epidural with blood loss and lots of stitches I could have done with more help on the ward but the staff were run off their feet. It was so loud and stressful on the ward I didn't argue when they said I could go. There seemed to be a bit of a baby boom in Sept/Oct 2007. Hopefully it will be calmer when you go in.
I've met lots of mums since my dd was born and haven't heard anything terrible about Derriford apart from the delivery rooms aren't pretty and they're very busy.
I gave quite a detailed feed back to the NCT who were consulted by Derriford to help make improvements as they were aware of problems. Hopefully things will have improved there now.
All the best for the birth. I'm sure you will be fine.