To buy or not to buy.. that is that question.
Ask yourself these questions,
1. Will the CX Housing Allowance pay off that mortgage during the time scale you are willing to live in HKG? (With a conservative interest rate factored into your calculations)
2. Can you (and your family) live in that property for the same period.
If so, then why not use the housing allowance to supplement your meagre pay and retirement package. 500k/per year over 15 years is 7.5 million extra income, but that comes with ties to CX/Hong Kong and some risk.
There are various generations of CX pilots who have widely differing perspectives on this.
My generation had to pay 30% cash down for their high-rise appartments, and paid interest rates above prime (typically prime +1% or more). We only got the full rent free zone when actually promoted to JF/O, unlike the current 2 year automatic progression. We went through the property downturn of 98/99 and consequent negative equity era (coupled with job insecurity 1999-2001), and naturally have a conservative persective.
There is now a generation of pilots who bought in 2003/4, who were able to get 90% financing (or more) mortgages (at prime -2.X etc). They were then able to enjoy a couple of significant surges in property values in late 2003 to 2005 and 2007/now. To this generation, use of the housing scheme to make millions, seems like a "no-brainer".
There is nothing new about this situation in HKG for CX/KA pilots. But most of the guys who suffered through high interest rate woes in the 1980's are gone now, so we only have the Pokfulam property millionaires input from the few remaining very senior A scale senior captains. But the lessons remain the same.
For me, it makes sense to be exposed/tied to the property market in HKG, since my asian family and I are likely to remain in asia for good. We consider the CX housing allowance as paying off the mortgage on our current home. This will fund our future home somewhere else (hopefully cheaper) in asia. If our HKG property does well, then we will consequently live well. But conversely if our HKG property does not do well then our living circumstances may suffer.
Note, that I do not consider the housing allowance as likely to generate a profit or any extra income/saving. Simply a place to live, which will be debt-free at 55.
As pilots we are used to planning alternatives etc. So basically, while one should consider "nothing ventured, nothing gained" with regard to using the housing allowance, you should also be prepared to live with a downturn.
Be careful with over 70% financing, since the finance costs increase significantly.
Be very careful about financial commitments while you are facing any upgrade selection process. Any mortgage will typically have a penalty phase of 2 years, so if there is any chance of your circumstances changing within the next two years then do not lock yourself in. This includes SO to JFO, or Command upgrade. Personally I did not buy until I had passed my QL, since there was (in those days) a significant wastage rate.
Just think, if I fail my PK/QL/three bar etc... with this mortgage, then how much pressure will I be under!
Or, with packages so much better everywhere else, why am I stuck here in HKG with this mortgage for the next 15 years!
Good luck!