I also got my HRP in 3 weeks. I saw on this website, how others got a 1-4 month delay, just for verification of the sheng ming shu, and after the delay, they had to make a 2nd trip to HK, just to apply for an HRP, and then wait 3 weeks. I also saw that the requirements now were HKID, HK Passport, and HK birth certificate. So I was psychologically prepared of what I had to face when I went to HK in November...
I was born in HK with ***AZ on my HKID, HK passport and US passport. I also brought my HK birth certificate. At the CTS in Kowloon Bay, I 1st presented HKID, and HK passport. Agent 1, seeing I got my HKID only 4 years ago, asked to see my foreign passport. I showed my US. She then gave me the HRP form, and sheng ming shu to fill out. She said the sheng ming shu was because of my recent issuance of my HKID. However, I was also allowed to apply at the same time.
After filling out, with help from staff that was walking around, I finally turned in my applications. At the end I was told the birth certificate was not necessary, since I never changed my name (only if you changed your name, then they will require the birth certificate).
In a not so related matter, my friend was also allowed to pick up my HRP for me, since I won't be in HK by the time it's ready (I assumed 2-5 months). To do this, both mine and his HKID, and also the receipt needs to be copied on 1 paper, and he must keep the original receipt. But my friend got a call from them, and picked it up in just 3 weeks after I applied.
So in conclusion, I was able to turn in everything on the single visit, and unlike others, I didn't need to return to HK for a 2nd time, just to apply. I was so happy...