Even though CX flies from JFK I consistently take the flight out of YYZ due to the amount of bonus miles that have been offered over other North American gateways. That coupled with discounted milesage upgrades to 1st have certainly made the extra leg worth while. (LGA-YYZ). As previously stated, it is an A340 and you do have to stop in Anchorage for fuel in the middle of the night. IMHO the business class product on JL and CX are very similar. Another option that I do not believe was mentioned is AA to NRT and then CX to HK. As I am certain you already know, you will not receive any qualifying miles on a JL flight, unless it is ticketed as an AA flight/codeshare.