I had my first there in 2015, as did several of my friends (so this may be dated). I’ve since had a second baby at a different hospital. I had an induction which failed followed by an EMCS.
It’s a very busy London hospital. Much of it is quite old but the facilities were adequate - although the birth centre was closed that summer but I ended up on the delivery unit anyway. Most of the staff were very pleasant with the odd notable exception. They gave you a booklet which started off by telling you not to bother asking for a planned section because they wouldn’t give you one without a medical reason, which had me a bit 
.
Antenatal care was adequate. Fine once you actually got there - I got the right appointments at the right times - but if you had concerns you could never, ever speak to anyone - the triage number would just ring and ring.
The induction was handled really badly. Clinically, the care was safe, but it was not good. It’s not the kind of hospital where people sit down with you and discuss pros and cons - it’s all so busy and automatic you just get told what they’re going to do to you. So be prepared to ask awkward questions and advocate for yourself. The EMCS happened at the right point, which was the main thing but again, it was not patient-focused (they took the baby out of theatre while I was being stitched and the medics just talked over my head as if I wasn’t there).
Postnatal ward was very busy and not particularly pleasant but imagine typical of other NHS hospitals.
My friends who had babies there were broadly happy. It was stereotypical NHS - great in an emergency but a distinct lack of the fluffy stuff.
We moved so our second was born outside London and that was a much better experience!
I think your other options there may include Homerton but I also know people who used the Barkantine birth centre and UCLH and they were both really happy.