For what it is worth, I was with Korean for 6 years. For guys who managed to avoid tax, the money was fairly worthwhile when the greenback was strong. However, there were many cons; back in the early 2000s KAL was under close scrutiny by FAA, CASA, NZ CAA and many other regulatory bodies. As such crews were subjected many surprise flight checks, ramp checks, CASA and FAA audit checks, DOD audit checks etc which made life stressful especially when you get less than sterling performance from your Korean F/O's and augment captains. Things improved after the mid 2000s but with their recent close calls, I believe all the regulatory bodies are going to tighten the screws again.
Then as someone had mentioned, the nagging worries when you deadhead or when your families travel on KAL services. Add in the constant rechecks for trivial anomalies in your medical lab tests and their insistence that captains in the 50s remain spritely like spring chickens. life can be tumultuous roller coaster of swinging emotions. I read somewhere that one guy reckon he aged 3 times the rate of contemporaries in other outfits; it was also true in my case.
In a nutshell, I WILL NOT DO IT AGAIN. Having said that, the KAL deal was the best commuting contract. I just wish that all the recruitment agencies work out such commuting contracts with VN, Jet, AI, EY, EVA, CAL, JAL etc.