Overall he's good. Although sometimes he can act selfishly, but his intentions are always good. There is only one thing that keeps this man going: Sydney. He doesn't care what he does - legal or illegal...he will do everything in his power to protect her. Even though their relationship was not on the best of terms when she was growing up, he always loved her. Since he discovered Irina's secret, he had tried to shut himself emotionally. He believed at one point that his emotions nearly drove him to the edge, but now he's soften a bit...and I mean a little bit. Looking back from the 1st season, he's opened up (emotionaslly, that is) so much.
Simply said, he just has an intriguing personally...that's what makes us love him!