I found it underwhelming to be honest.

The SYD F lounge is okay but you can get in there without flying in F if you are a Gold.....so it's not that exclusive and can get busy. The SYD-SIN sector is a strange flight - only 8 hours long but our cabin crew treated it like an overnight flight. They served the meal then basically shut up shop and went to sleep as did most of the other five pax.
One doesn't have that much time to relax in SIN so before long you're back on board hot, tired and not very hungry....sleep is the main priority on this flight rather than enjoying the F service. A speedy meal service then lights out.
All in all the trip can be enjoyed just as much in CW I suspect.......in fact the best bits of F are the SYD lounge at one end and the CCR dining room in the Arrivals Lounge at the other end.

Having said all that if it's your first time flying the route and you have the miles then go for it.