Hey Durban girl,
From what we could see so far, it all seems to be random. For sure girls have to wait significantly less, while guys usually around 3 montghs.
It also looks like they try to keep some kind of order, for example those who had their FI's in the middle of october and received "on hold" mail, already got or will get soon GC, those who had FI's in the beginning of november are still waiting. And also we have those who had some problems like missing photo or some documents, this for sure delayed whole process.