Training is the same but you get a P2X rating at CX. Basically, you can't use the rating anywhere else. The only reason really is to keep you from leaving as far as I can see.
A good friend just finished his IOE on the B777. He spent just shy of four years as an SO, but he was on bypass pay for, I believe, about a year of that.
The SO thing at CX is not so great. We compared what we did, as I was an SO at Air NZ, and I know the QF score as well. He said that they never flew below cruise, never had a command practice leg etc., but were expected to shine in the sim. At Air NZ, the SO's get command practice legs (all flight planning decisions, fuel decisions, cockpit set up and all briefing's less the OPT performance) and can fly until transition or 10K. Most guy's hand fly, so you do get hands on. My friend at CX said that would be unheard of there. Plus he was not in the least impressed with the general attitude on the B744, so try to get the 777-3000.
I'll ask about pay scales. I can say that he did about 50K in HKD per month for housing, so that is good.