Hi,
Please try not to worry (too much anyway).
Whilst my experience of UCLH was really awful, 3 ladies from my NCT group all gave birth at UCLH (within 2 weeks of each other) and they all had fab experiences.
Personally I think that you will find as many positives as negatives in terms of experience from any NHS maternity wing.
Having a good birth experience unfortunately isn't something predictable. Many things along the way can colour your experience/outcome for you and not all of it is down to the team handling your care.
Granted, if you're as unlucky as I was (a bad combo of birth gone wrong and team handling care not working together/communicating, bad postnatal etc etc) then you would feel annoyed with the hospital. However that could just as easily have been another one of the maternity wings in London.
I also blame myself. I did not speak up for myself (this is very unusual - normally I am quite vocal and happy to make demands). If I had put more effort into demanding certain things along the way, perhaps my experience would have improved greatly. Also DH was birth partner and I didn't brief him properly as to what I would want along the way so he was flapping around like a big useless thing not knowing what to do or ask for.
I think that you should focus on being calm and collected in your last few days. Write down your ideal birth scenario, then also write down a list of interventions you would like if things don't go to plan. Talk it all through with your birth partner/DH/DP so that s/he is fully informed of how you wish to proceed if things do not go so well and so that s/he can ask the right questions and make the right/timely demands of the team handling your care.
Most of all, try not to have too many expectations (or too high expectations) of how your birth may go in the end. There are so many things during the labour and birth process which are outside the control of you/birth partner/birth team.