If it had been a night flight, I would have suggested CX for the flat bed. Since it is daytime, I would lean towards QF since I think it is more comfortable for a daytime flight than the CX product
Whether it is worth requesting an upgrade to F depends on whether you have a nice stash of miles. First is nicer and you would get to try out the 1st lounge in Sydney, but for a daytime service , business is pleasant
I would request the upgrade if I had enough spare miles if it was me
Dave