If you happened to be in Korea by chance and will reside there at least for months to come. You should definitely wait. If not, you don't need to. Samsung probably will do the exact same again as they did last year with GS4 LTE-A only for Korean market.
Nutgrafs – Galaxy S5 variant with QHD(2K display, 2560X1440) for Korean market spotted in GFXBench
Nutgrafs – Galaxy S5 variant with QHD(2K display, 2560X1440) for Korean market spotted in GFXBench