Yes, I had this experience. With my first child (now 3-years-old) I chose to go back to the USA to give birth. At the time, my work allowed me to leave early and come back later after he was born and my husband could get leave time to come be with me. I went back to the States when I was 7-months pregnant and my husband joined me 2 weeks before my due date. I stayed with my mother at her house.
I chose to go back because I'm not a huge fan of the HK maternity system overall and at the time I was younger and wanted to be near my family for my first birth. I also was able to go through a midwife program at the hospital I gave birth at so I didn't have a doctor and was able to give birth "on my own terms" (not with a doctor standing there directing me on what to do and when to do it--like the docs in HK like to do) with my husband present. My husband was my birth coach (we went through a 12-week program to prepare for this) and he was able to catch my son when he came out and cut the umbilical cord, be there for the first bath and baby and my husband were able to room-in with me in recovery. My mother was also able to be there supporting me when my son was born. At the hospital I gave birth at you were literally allowed to have as many people as you wanted attend the birth. I had an excellent midwife who was on board with my beliefs about childbirth and supported me and when I had too much bleeding after my baby was born she saved my life. I had access to a tub of warm water while giving birth to help ease the pain and the hospital was set up like a birthing center so there were a lot of things you could use to make the birth easier--I don't think most hospitals in HK have anything like this.
The down side to going back to the States was that I had to be separated from my husband for a few months. Also, staying with my family after the baby was born tended to be stressful as it wasn't my own home so I didn't feel as relaxed. Also, we didn't have a helper there to help with the baby and my mom was working full-time so it was just me and my husband which was really exhausting--especially because I physically was very weak for many weeks after the birth because of the complications I had. It was wintertime so we couldn't really go outside and enjoy the fresh air because it was just too cold.
Also, we had to pay for the birth out-of-pocket (maternity insurance, unless covered by your employer usually equals out to as much as just paying out-of-pocket anyway) and that ended up being about $8,000 USD and that didn't include the price for airline tickets (and even babies have to have a "ticket" when traveling internationally and the price at the time was about 20-30% of an adult ticket), food and other expenses while we were in the States.
Also, the flight itself to and from the US was pretty brutal--flying when you're 7 or 8 months pregnant isn't very comfortable and especially if you have a long flight. To get to my hometown I was literally traveling for almost 30 hours and in the air flying for about 20 of that. It may be better for those living in a major city. Coming back with a baby on the plane was no picnic either--even though I had my husband's help. I had to pump breastmilk in the restroom on the plane (nasty) and there is nowhere to change a baby's diaper on most American planes so my husband had to change diapers literally on his lap.
This time, I didn't have the choice of returning to the States as my work situation wouldn't allow for it so I gave birth to my daughter in Hong Kong. I planned on going through a private hospital but my doctor bailed out on me when I was 38 weeks pregnant.
I gave birth in a public hospital and everything went well--but the reason why it went well was that we were really prepared and stood up for what we wanted when the hospital staff tried to do whatever they wanted with us. I don't think I would have known how to do that if it was my first child, though. And the thing is, public hospitals vary so much from hospital to hospital--some hospital experiences can be great--others can be frightening and it all depends on the hospital and the staff on the particular day you give birth so it's really the luck of the draw, actually. At least in the States, I knew what I was getting myself into--I had taken a tour of the hospital I would give birth and knew the staff well and knew my midwife well so I felt comfortable. Here in HK, I feel like the private hospitals are a money making machine where Mainlanders go to have their kids (maybe Matilda is the exception) and aren't any better than the public hospitals and may even be worse.
So, if I were you and planning to stay in HK to give birth I would just go with the public hospital but definitely be prepared and have someone with you (your husband) to stand up for what you want because my experience is that otherwise you may get walked all over.
Best of luck choosing the right option for you.