I lived in south korea and i'm korean.
Our country provide WCDMA/CDMA service.
WCDMA Band cairrer are below.
SKTelecom (2100 Mhz)
Korea Telecom (2100 Mhz)
CDMA band carrier is below
LG U+ (1800 Mhz)
But, Our local galaxy s radio band spec is poor then EU galaxy s2.
<< Korea Galaxy S2 Network support >>
Double band UMTS 900/2100
Triple band GSM 900/1800/1900
<< EU Galaxy S2 band Network support>>
Quad band GSM 850/900/1800/1900
Quad band UMTS 850/900/1900/2100
Yeah, Our korean prefer TDMB(TV Service) then multiple band support.
So it will occur H/w problem occur and samsung select some frequencies killed.
The main critical issue is
if you purchased in our SKT galaxy S 2 model (SHW-M250S),
may be you can't receive MMS. because our carrier SKTelecom using
their own MMS format. (SK-MMS)
Most of world using OMA-MMS.
So it will occur many sms, mms problems.
and our service porvider (SKT, KT) they enjoyed add a many many bloat ware.(Service program).
it will occur a tons of system hang and reset problem.
As a result, i recommend that if you purchased galaxy s2,
wait a your country's carrier galaxy s2( like captivate or fascinate) nor buy the EU galaxy s2.
So, I can't recommend our korea's galaxy s2.
I'll buy a EU Galaxy s2.