Went from Melbourne to Tokyo with 2 young kids (9 months and 4yo). Got allocated seat with baby bassinet at the front row. The seat setting on the plane is 2-4-2. Baby bassinet is attached to the front wall, in front of the 4 seats. However, since we paid for 3 seats (9 months old baby doesn't have allocated seat), we only get 2 seats in the middle and 1 seat on the left. This is to allow other family with baby (if any) to use the other baby bassinet on the other side of the 4 seats.
My seat on the left is also the seat that people gets when they paid for extra leg room.
Flying with baby bassinet is an added convenience. There is no way the baby is going to stay sleeping there for the duration of the flight (that's just a silly daydream), but it's nice to have a place we can put the baby when she's actually sleeping.
The bassinet can be flattened back to the wall when not used. We had to do this during take off and landing.
Flight attendance are more than helpful. They went extra mile to help us with anything we need and beyond. Without we ask, they went offering toys, water and other help throughout the journey.
On the other side, we also did our part to do everything in our power to keep the kids "peaceful", to minimise the trouble they might cause other passengers. When baby was crying, my wife and I took turn to hold bub, walking around until she called down or fell asleep (our baby fell asleep much easier when cuddled while walking around).
The only inevitable crying was during take off and landing. We were not allowed to use baby bassinet and we couldn't offer toys for the baby because our cabin bags had to be stored in the upper compartments. That resulted in dramatic crying. We learned our lesson to always prepare toy/distractions for our baby that remains on our hands when all our bags are stored away.
We love flying with Qantas and will always consider it as our first option when we plan a trip. This experience makes it even stronger as the top airline in our list.