Pros
If you are Korean and want to work at a top Korean company, you can work there. It has some status among non-corporate types in South Korea.
Cons
They have different tiers of workers but that is not made explicit. One worker in one department or group will make double to triple what other similar workers make due to the name of their university, prestige of previous job, or other inscrutable factors, like how close you are to HR in your department or if you are located in Seoul vs. Suwon. Compensation is bad. They make a big deal of paying for housing and relocation for foreign workers, but all major companies do the same when relocating and recruiting international workers. They use funny math to somehow make a $30K/year offer look like $125K on paper. They say they want to internationalize but then make everyone follow 50 year old Korean corporate structures and rules. Some people are allowed to break the rules, while others have to follow the strict rules to a T. A completely schizophrenic company that survives because of the prestige factor of working there amongst Koreans. The other thing, they will recruit foreigners with great fanfare, telling them how they will make great money and have a chance to expand their careers. In truth, as a foreigner, you are excluded from your work groups for not being Korean, and then given low marks for "cultural assimilation" when bonus time comes around due to low integration with the team. Your bonus comes in low, and your chances for advancement drop significantly.