I think mainland China is a better country to teach EFL in than the ROK is. The ROK's visa rules suck and for a developed country the way its hagwons treat FT's is an absolute disgrace. Key money is a load of bull too. The Korean public do not respect foreigners, unlike what happens in China. Most foreigners who've taught in both countries say employment teaching English in China is better as a package, but the private educational sector in China is generally a minefield of deceit.