Looplu I had both of mine at the whit! I really liked it (was also treated for my mc there).
Like all big London teaching hospitals, it can be hit or miss but overall I was happy with it. There was only one midwife I was truly unhappy with. The postnatal ward can be grim (but most of then are in London from what I can gather!). But good Breastfeeding support.
Lovely birth centre just one floor from labour ward if you need to be transferred for a epidural or anything. Home-from-home style and partners can stay over. But some of the labour ward delivery rooms also have birth pools and active labour/delivery is encouraged.
Amazing home birth team if you go that route (I wanted a home birth first time - meant I got all my midwife apps after a certain point at home, which was fab! Although ended up induced/having a crash section so not quite what I'd planned! I still highly recommend the hb team though).
If you choose the Whit, I would highly recommend self referring and saying you want to be under the care of Amali Lokugamage - she is an amazing consultant, who had her first at home in her early 40s and has become a vocal proponent of natural birth and emotional well being in birth (she was present during ds's c-section birth - the whole thing was nightmarishly stressful and she was the one hcp who made time to be properly kind to me and dh - second time around I self referred straight to her!).
Chances are you won't see her but you're assigned to the care of someone and better her (or a registrar who works with her) than someone else if you do need to see an obstetrician about anything!
Sorry for the ramble. I've had friends happy with uch too. So factor in things like the ease of getting there (eg uch would have been good for me leaving work for antenatal apps but nightmarish to get to from home).
And if you fancy a doula I loved mine Mars lord (mammy doula) - she made my vbac with dd much easier. Wish I'd had her first time around. Also recommend the hackney doula (a friend from my march 2010 antenatal thread!).
Also Nct classes are a great way to make a bunch of friends for maternity leave - I'm still in touch with all of mine from my first pregnancy. They book up quite fast as far as I remember...
No longer a North Londoner btw. I lived in Stroud Green, so lots of lovely time in crouch end and finsbury park with my babies. I live in the US now, so it's going to be different with no3!