The dramas main flaw is the story line. I think if had some minor tweaks it could have been a great show. With that said it wasn't your typical love triangle and I genuinely didn't want any of the male leads to get the girl.

I loved the character of "Gong Ji Chul / Jong Bum". They did such a great job with both sides of him. I really liked the emotionless version and his sincere desire to know how to feel. That is where I began to find fault with the female lead, her concern for him was patronizing much of the time and seemed to devalue who he was.

Other than that - they all actually did a good job to me.