Having done the CX 2nd interview, I can say that you will see your a**e on the sim ride if you have no heavy experiance. It doesn't have to be a 747-200. There are L1011's, etc out there (eg Bournemouth) where you can try flying anologue display ac and get used to heavy's. I was informed in advance from collegues who pole 747's that they're easy to fly. Well I guess they are when you're shown how.
Get used to inertia, momentum, climbing at 250knts, etc, and if you don't close the throttle you will never slow down.
Also know why they use EPR readouts over the N1 power setting. If you crack the nod for a 2nd interview, get some sim time, or you're wasting your time in HK. Only takes a few hours on the sim and it should make a world of difference.