I haven't personally seen both, but I know choosing a Muslim gynae matters a lot especially for comfort during examinations and delivery, so it's worth thinking about whether location or waiting time matters more to you. NUH and KKH both have their strengths, KKH being a dedicated women's and children's hospital so some mums feel more at ease there for high-risk or complicated pregnancies. If the doctors' styles and communication matter to you, it might help to book a one-time consult with each and see who you click with before committing. A friend of mine saw a Muslim gynae at KKH and said she felt very comfortable and well-taken-care-of throughout her pregnancy, which really made a difference for her peace of mind.