It all depends on what you want out of life. a HKG based SO probably earns 2x that of a 320 driver, especially after 2 years when the housing doubles. Yes you can stay driving a 320 around for the rest of your life but if you want to be able to retire comfortably you need to get onto a widebody payscale and there arnt that many jobs out there that will hire you onto the right seat straight away.
"4 years as an SO", those days have passed, a chap i spoke to today is doing his in 3 years and it is only getting shorter. Now say you join CX at 30 and retire at 60.... it will be 60 by then or more likely 70.... then it means you give up 3 years of flying for 27 years of wide body FO/ CPTs pay.
As an SO you will have on average 15-20 days off a month. If you are so desperate to fly then go to Aus or somewhere and hire a lighty.
My time as an SO were awsome i travelled the world. set up investments, spent time with the wife and family we fishing played golf ....etc....work was a very secondary even tersary part of my life for 3 years and it was fantastic.
If this doesnt convince apeal dont bother coming, it make a long flight sitting next to a down and out SO, it makes a great trip when the guy is keen and making the most of the oppurtunities offered them.