jumpseats on the 400 is 2 business class seats, pretty neat but be prepared to be moved down to cabin crew seats if the crew needs to use them (only eligible persons are allowed to apply for jumpseats). and nothing is ever for free in cathay. even if you request a cabin crew (door) seat down the back at check in (if the flight is completely full) you still have to pay ID90 economy fare, which is around 900HKG one way HKGLAX.