I just got engaged to a beautiful Korean lady I met on KoreanCupid after I searched many other sites. We contackted once on the site, exchanged emails, facebook profiles and skype, so we were sure both parties are for real. Then I visited her in person. We are both very happy and in love!!
Pros
You can easily spot a scammer. Never include personal info, send money. Verify the person on fb and skype. KoreanCupid screen their members.
Cons
Like all sites, scammers are everywhere. Avoid anyone asking for money.