I am curious why you would buy a Y full fare ticket if these are personal trips you pay out of pocket? In my experience, discounted J tickets often are cheaper than Y full fare tickets. And on an ultra-long haul ~24 hour journey the lie-flat seating and lounge access is very nice.

My sympathies about the delays... CX does tend to have a better track record than other airlines (say mainland Chinese airlines or *gasp, Air India?) but even a first tier operators has off days... case in point, look at how the reigning world champs Spain got spanked by the Dutch team in this first round of the world cup.

Your example is the worst kind of delays, the "creeping" delay. If CX/KA could have given an accurate 3am delayed departure time from the start that obviously would have been better but of course in the super complex world of airline ops, back up plans often don't go smoothly either in the case of irregular operations.

That's good to hear CX/KA recognized they messed up and offered up a decent 15k mile compensation. I'd value 15k miles at ~200 USD so that's equivalent to CX paying for a hotel room and a hot meal during the night of your delay.