I had a very difficult labour (ending in EMCS) at the Whittington.
However, the staff were brilliant - so supportive and calm and lovely. If it's going to go wrong (and obviously I hope it doesn't) they are the people you want looking after you.
In terms of aftercare, I couldn't move for people trying to support me with BF and they were very generous with their time despite clearly being overstretched.
They've got a brand new midwife led birthing centre there now as well.
But...I have a friend who had a less positive experience than me there. Equally, I know someone who had a horrific time at UCH as well as someone who had a dream birth there.
What I'm getting at is that these are big London hospitals that deliver hundreds of babies every year. There will always be some poor women who catches a midwife on a bad day on a double shift when the ward is full to bursting. Try to put any scare stories into this context - I would be amazed if any hospital could boast a 100% patient satisfaction record.
The thing you've got to remember that the women who post their birth stories on the internet are a self selecting group. You are far more likely (understandably) to rant on about how crap somewhere was and how pissed off you are at their shoddy treatment than to bother logging on to post about how nice it was and what a good experience you had.
I'd suggest visiting both the Whittington and UCL. Do the tour, speak to the staff and get a 'feel' for them.
Trust me, when you're in labour the last thing you're bothered about is a bit of peeling paint - you just want people you feel comfortable with and who you trust to deliver your baby and support you. And the only way you'll get any idea of whether this is the case at either hospital is to go along and see for yourself.
Good luck with the birth.