Hello, my second was born Kingston and I could not fault it. It's small and has a cosier feel than the larger hospitals.
My first born was born at St Marys, Paddington , amazing staff during the labour but the aftercare was horrendous with some pretty horrible temporary staff and breast feeding Nazi midwives and being in an overcrowed ward after she was born. She was born during the August bank holiday though and had to be induced, whearas I had a straight forward birth with my son who was born at Kingston and left after a few hours but I had a private room after he was born..
it really depends on so many factors, I'm afraid. I would go with the one which offers the easiest antenatal appointments. But you may be offered a private room at Kingston unless they are very busy after the birth.
My experience with St George's (not labour) has always been very positive.