Watching this after the original Criminal Minds, I could say, Korea did a pretty good job. Only certain parts, too slow and frustrating. One of the frustrating part is, Kang Ki Hyung's character is too stiff and serious. Aaron Hotchner still has his quirky sides.
But overall, it was good. I wouldn't recommend watching CM: Korea after the original CM. Watch the Korea version without the knowledge of the original CM, you will be fine.