From my experience, they are all very busy. I started with a well-known specialist in Central before moving to Baptist in Kowloon, and it was the same. Waits were an average of 15-45 minutes with an appointment. I don't know if you work full-time, but I do, and it's really a hassle.
Baptist is way more Chinese -- lots of mainland women, some of whom don't seem to know that you even need an appointment!
I've been to Baptist dozens of times, and I'd say a 30-minute wait is normal. I found them marginally better than the guy in Central, since they have a big team of nurses and doctors. The few times that I had an urgent case (threatened miscarriage) they were good about letting me jump the queue and / or setting me up with another doctor who was free.
Twice, I've had a weird experience where the doctor was pulled away to a "meeting" for a long time. Usually, I would then ask the nurse, who'd recommend that I go out for a coffee / lunch and then come back.
Dashing away for an emergency delivery I understand... but a meeting?
Still, I am generally happy with them.