I attended classes at Matilda. There are 6 classes in total and the classes are taught by Matilda staff, although in our case it wasn't the midwives from the maternity ward. One class was on breastfeeding, which was held by Sarah Hung, who is the Lactation Consultant at Matilda. One class was also taught by Yvonne Heavyside, who is a Health Visitor and takes alot of the classes/groups at Matilda.
We also had one class on pain relief and it was taught by Dr Richard Ooi, who is the resident anaethesist at Matilda. We also got a tour of the hospital wards and an explanation of what happens in the delivery room during labour.
Although Annerley is more convenient, I did find it useful getting use to going to the Matilda, meeting up with other parents who are about to give birth at the Matilda (we did bump into quite a few when we delivered and even made friends with a few of them) and for me, since it was my first, I felt a bit better familiarizing myself with the delivery room and the maternity ward, even though I had taken a tour of the hospital 6 months before.
The class had about 12 couples in it. As I signed up for my course a little late, I ended up straddling 2 courses to ensure I made it to all the classes before I gave birth and I ended up going to half my classes at the Matilda Clinic in Central and half my classes at the Hospital. So, do call the Matilda and ask about when the classes are in Central if this is more convenient for you.
I think the classes are going to be very similar in nature but it's really what works for you. Either way, make sure you also use the class as a social occasion and take it as an opportunity to meet other soon to be parents. We have become great friends with one couple and see each other regularly.
Either way, I do suggest you sign up for your classes as early as possible.