That's a surprisingly balanced view you've got on this thread. I always say to people that if you're young, single and don't mind sharing a small flat with a bunch of mates then it's a good gig for a few years but if you've got any children then it's sadly not.
CX pay 70% of your basic school fees but the fees count as cash so you're taxed at 15% on those fees. Given HK$90k school fees, that's HK$36.5k/yr per child from your own pocket. In addition, every school also has some sort of debenture/levy and CX don't help with these at all. The cheapest of these is probably about HK$40/yr so that's a minimum of HK$76.5K per child per year.
If you've just the one child, don't plan on having any more and will be happy living in an 800sq/ft flat (check with wife!) then you might be able to make it work but I find it hard to believe there aren't more appealing options out there.
Good luck.