Yes, I gave birth there last year. Overall, I was happy with the hospital and would go there again.
Ante-natal care is generally done in the community by teams of midwives. You rarely see the same midwife twice, until you get to the later stages of pregnancy, but I was happy with the care I received. They were great post-natally - weight issues meant we had quite a bit of contact with them. They support home birth; a friend of mine had a home birth with them (first time mum) and was happy with the service she received.
They have a birth centre which was closed due to staff shortages in the summer - I understand it's reopened. The rooms looked good, though, and some had pools. They run tours on Tuesday evenings. While it was closed, some of the rooms on the ground floor in the delivery suite had been turned into low-risk rooms and there was a pool or two.
It's a busy hospital and midwives are definitely stretched, though I had one to one care as I was induced. All the midwives I encountered were lovely, bar one (who we unfortunately got stuck with when I was being induced; think I was just unlucky). And I met a lot of them as I was in for the best part of four days. The maternity block looks a bit battered but it had a very friendly feel to it - much more so than Newham, where we ended up when DS was re-admitted due to weight loss post-natally.
I ended up with an EMCS (failure to progress), and the surgical team were brilliant, especially the anaesthetist.
Post-natal care left a certain amount to be desired, as I understand is generally the case - clinically, it was fine, but the staff are so over-stretched.
Breastfeeding support was good but patchy - we had some great, very sensitive, support from one midwife, which included using alternative methods to a bottle in order to feed DS a little formula. But you do have to ask for help - they're very willing to give it but may assume you are ok if you don't ask. There is a breastfeeding counsellor available, at least on weekdays.
It's a big London teaching hospital - as with most of the NHS, great in a crisis, look elsewhere for the fluffy stuff, ask questions/ask for help when you need it, and bring someone to advocate for you if necessary!
I know quite a few mums who've used Whipps in the past year - all have been broadly happy with it, although one friend did have a mismanaged third stage of labour which was due to staff being overstretched. Also know some people who have used, and were happy with, Homerton, UCLH (very happy) and the Barkantine (ditto). Not sure exactly where you are, but these may all be alternatives to Whipps.
Sorry, just realised this has turned into an essay - hope it helps!