So they gave you basically $638 for free because you whined about a (relatively) tight connection you booked yourself, and yet you call them "worst airline"?

Ungrateful US-American, one could say..

by the way, if your flight gets cancelled in the US, they won't even pay your overnight accomodation.. and flight cancellations there happen very often.. oh, and the crews rarely if ever speak _any_ other language than English.

So yes, plenty of worse carriers than Air China, like all US-American ones..