I used Control Global and only had one minor problem - that I didn't read the payment options properly. On the day I went to pay them and pick up my car from the wharf, I was shattered when told they only accepted a bank cheque / cash (I had a personal cheque). But that's my bad. Came back the next day with the bank cheque and it was fine. They had previously organised the AQIS inspection (car was clean so it didn't need to go to Hobbs), and they gave me all the paperwork I just took it down to Glebe, and they gave me the keys.
PS - car will be empty of fuel so if you are driving it away, bring a jerrycan.
This time (another car on boat as I speak), I'm trying to do it all myself, save a couple of hundred dollars. Bit of a learning curve but if it all goes well (I'll know next week), then I'll be more than happy to help anyone with the process.