Pros
They pay well. That is the only reason as an expat to work for them in their HQ. Nothing else particularly good to say.
Cons
There is zero opportunity for professional development. There seems to be a general lack of trust in non-koreans and therefore an unwillingness to give them the access to the information etc they need to perform their duties. Which in turn renders them ineffective. The management system is extremely hierarchical and top heavy, and there is a complete inability and unwillingness of any non-executive to make a decision. The way projects are managed is with arrogance and a huge superioty complex to non-koreans, which when coupled with the general lack of experience and knowledge in managing projects internationally is a recipe for disaster.